Internet Engineering Task Force Alan Johnston Internet Draft WorldCom Document: draft-ietf-sipping-service-examples-03.txt Robert Sparks Category: Informational Chris Cunningham November 2002 Steve Donovan Expires: May 2003 dynamicsoft Kevin Summers Sonus Session Initiation Protocol Service Examples Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026[1]. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract This informational document gives examples of Session Initiation Protocol (SIP) services. This covers most features offered in so- called Centrex offerings from local exchange carriers and PBX (Private Branch Exchange) features. Most of the services shown in this document are implemented in the SIP User Agents, although some require the assistance of a SIP Proxy. Some require some extensions to SIP including the REFER, SUBSCRIBE, and NOTIFY methods and the Replaces and Join headers. These features are not intended to be an exhaustive set, but rather show implementations of common features likely to be implemented on SIP IP telephones in a business environment. Johnston, et al. [Page 1] Internet Draft SIP Service Examples November 2002 Table of Contents 1 Overview...................................................3 1.1 Legend for Message Flows...................................4 1.2 Document History...........................................4 2 IP Telephony Services Features Call Flows..................8 2.1 Call Hold..................................................8 2.2 Consultation Hold.........................................19 2.3 Music On Hold.............................................34 2.4 Unattended Transfer.......................................41 2.5 Attended Transfer.........................................48 2.6 Call Forwarding Unconditional.............................59 2.7 Call Forwarding - Busy....................................64 2.8 Call Forwarding - No Answer...............................71 2.9 3-way Conference û Third Party is Added...................79 2.10 3-way Conference û Third Party Joins......................84 2.11 Single Line Extension.....................................89 2.12 Find-Me..................................................105 2.13 Call Management (Incoming Call Screening)................115 2.14 Call Management (Outgoing Call Screening)................119 2.15 Call Park................................................122 2.16 Call Pickup..............................................131 2.17 Automatic Redial.........................................138 3 Security Considerations..................................144 4 IANA Considerations......................................145 5 Acknowledgements.........................................146 6 References...............................................147 7 Author's Addresses.......................................148 Johnston, et al. Informational [Page 2] Internet Draft SIP Service Examples November 2002 1 Overview This informational document provides call flows detailing a SIP implementation of the following traditional telephony services: Call Hold Music on Hold Unattended Transfer Consultation Hold Unconditional Call Forwarding Attended Transfer No Answer Call Forwarding Busy Call Forwarding Single-Line Extension 3-way Call Incoming Call Screening Find-Me Call Pickup Call Park Outgoing Call Screening Automatic Redial It is the hope of the authors that this document will be useful for SIP implementors, users, designers, and protocol researchers alike and will help further the goal of a standard SIP implementation for IP Telephony. It is envisioned that as changes to the standard and additional RFCs are added that this document will reflect those changes and represent the current state of a standard SIP IP Telephony implementation. These flows use SIP as defined by RFC 3261 [2] and SDP usage defined by RFC 3264 [8]. Note that this document is informational, and nothing stated here should be taken as normative. The SIP specification and the other referenced documents are definitive as far as protocol issues are concerned. Also, these flows do not represent the only way to implement these services - other approaches such as 3pcc (Third Party Call Control) or Back-to-Back User Agents (B2BUA) may be more appropriate in some circumstances. The design and principles of these service examples are described in the the Multiparty Framework document [12]. These flows assume the functionality described in the SIP Basic Call Flow Examples document [3], which explores basic behavior. Some of the scenarios described herein make use of the SIP method extension REFER [4] and the SIP header extension Replaces [5], the SIP header extension Join [6], and some of the concepts in the 3pcc (third party call control) document [7]. The SIP Events document [11] describes the use of SUBSCRIBE and NOTIFY while the SIP Call Package document [10] describes the dialog event package. These flows were prepared assuming a network of proxies, registrars, PSTN gateways, and other SIP servers that have a pre-established trust relationship with each other, secured through other means than SIP. User agents wishing to use the services in this network are required to authenticate themselves with an edge proxy using SIP Digest. To improve the clarity of this document, authentication of User Agents is not explicitly shown in all flows, except where authentication directly relates to the service example. Johnston, et al. Informational [Page 3] Internet Draft SIP Service Examples November 2002 Each call flow is presented with a textual description of the scenario, a message flow diagram showing the messages exchanged between separate network elements, and the detailed contents of each message shown in the diagram. 1.1 Legend for Message Flows Dashed lines (---) represent control messages that are mandatory to the call scenario. These control messages can be SIP or PSTN signaling. Double dashed lines (===) represent media paths between network elements. Messages with parenthesis around name represent optional control messages. Messages are identified in the Figures as F1, F2, etc. This references the message details in the table that follows the Figure. Comments in the message details are shown in the following form: /* Comments. */ 1.2 Document History The first version of this document was the Internet-Draft "draft-sparks-sip-service-examples.txt" October 1999. The next version was combined with the SIP Telephony Call Flows document into the "draft-ietf-sip-call-flows-00.txt" April 2000. This version is based on Section 7 of that document with many of the examples extensively rewritten using the REFER method. 1.3 Changes to 00 - Moddified all REFER flows to include 202 Accepted and NOTIFY result message. - Removed "Telephony" from title of document. - Added note on 2.9 on use of REFER to exit 3-way conference. - Modified Music on Hold/Call Park flow (2.2). - Modified order of messages in transfers (2.4 and 2.5) to more closely resemble PSTN experience. - Added Call Pickup flow (2.13). - Added editorial notes on usefulness of Replaces header. Johnston, et al. Informational [Page 4] Internet Draft SIP Service Examples November 2002 1.4 Changes to 01 - Added Replaces header to flows. - Changed handling of call hold. - Added Contact and Referred-By headers and ref parameters to REFER messages. - Changed some Contacts, Routes, and Request-URIs to IP addresses. - Incremented o= line when SDP is updated with hold. - Added From tags throughout. - Renamed Music On Hold/Call Park to Call Park and added new Music On Hold call flow using 3pcc. 1.5 Changes to 02 - Changed call hold flows to show sendonly attribute based on [8]. - Removed ref parameter from the Referred-By headers since it is now just a generic paramter in the latest draft [4]. (Note that if the ref parameter stays, additional characters such as "<", "@", and ">" must be escaped.) - Removed tags in CANCEL requests and responses. 1.6 Changes to sipping-00 - Added Max-Forwards - Added branch parm and received param to Vias - Changed Record-Route and Route behavior to show loose routing. - Added Record-Route and Contact to 18x responses - Changed Call Pickup to show Replaces with an early dialog - Changed description of Single Line Extension service - Changed Call Park and Pickup flow to show a different user picking up the call. - Added Allow and Supported headers to REFER and replaces flows. 1.7 Changes to -01 Johnston, et al. Informational [Page 5] Internet Draft SIP Service Examples November 2002 - Added SIP Events and dialog event package to Call Pickup flow. - Added Auto Redial call flows - Updated based on new Replaces draft with 481 behavior instead of using Accept-Contact in attended transfer. - Added Single Line Extension call flow. - Added Error-Info in call screening flows. 1.8 Changes to -02 - Added 3-way call flows showing transition from 2 party call. 1.9 Changes to -03 - Fixed owner/version SDP errors in hold SDP. - Add Notification of remote-URI in Call Pickup scenario - Updated 3-way conference flows to show just internal User Agent mixing - Added FQDNs in Contacts and SDP, changed example addresses - Replaced use of Accept-Contact header with Contact URI - Updated for refer-06 changes Johnston, et al. Informational [Page 6] Internet Draft SIP Service Examples November 2002 Johnston, et al. Informational [Page 7] Internet Draft SIP Service Examples November 2002 2 IP Telephony Services Features Call Flows These call flows show how a number of standard telephony features can be implemented using SIP. They are not meant to represent a complete set. Some calls make use of SIP extensions. 2.1 Call Hold User A Proxy User B | | | | INVITE F1 | | |--------------->| | | | INVITE F2 | |(100 Trying) F3 |------------->| |<---------------| | | |180 Ringing F4| | 180 Ringing F5 |<-------------| |<---------------| | | | 200 OK F6 | | 200 OK F7 |<-------------| |<---------------| | | ACK F8 | | |--------------->| ACK F9 | | |------------->| | Both way RTP Established | |<=============================>| | |INVITE(hold) F10 |INVITE(hold) F11|<-------------| |<---------------| | | 200 OK F12 | | |--------------->| 200 OK F13 | | |------------->| | | ACK F14 | | ACK F15 |<-------------| |<---------------| | | No RTP Sent! | | | INVITE F16 | | INVITE F17 |<-------------| |<---------------| | | 200 OK F18 | | |--------------->| 200 OK F19 | | |------------->| | | ACK F20 | | ACK F21 |<-------------| |<---------------| | | Both way RTP Established | |<=============================>| | BYE F22 | | |--------------->| BYE F23 | | |------------->| | | 200 OK F24 | | 200 OK F25 |<-------------| Johnston, et al. Informational [Page 8] Internet Draft SIP Service Examples November 2002 |<---------------| | | | | User A calls User B, User B places call on hold. User B then takes call off hold. User A hangs up call. Hold is unidirectional in nature. However, a UA that places the other party on hold will generally also stop sending media, resulting in no media exchange between the UAs. Message Details F1 INVITE A -> Proxy 1 INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 INVITE Proxy 1 -> B INVITE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 Johnston, et al. Informational [Page 9] Internet Draft SIP Service Examples November 2002 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F3 (100 Trying) Proxy 1 -> A SIP/2.0 100 Trying Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345601@here.com CSeq: 1 INVITE Content-Length: 0 F4 180 Ringing B -> Proxy 1 SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content Length:0 F5 180 Ringing Proxy 1 -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content Length: 0 F6 200 OK B -> Proxy 1 Johnston, et al. Informational [Page 10] Internet Draft SIP Service Examples November 2002 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F7 200 OK Proxy 1 -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F8 ACK A -> Proxy 1 ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 Johnston, et al. Informational [Page 11] Internet Draft SIP Service Examples November 2002 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 1 ACK Content-Length: 0 F9 ACK Proxy 1 -> B ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 1 ACK Content-Length: 0 /* User B places User A on hold. Note that the version is incremented in the o= field of the SDP */ F10 INVITE B -> Proxy 1 INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844528 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=sendonly F11 INVITE Proxy 1 -> A INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Johnston, et al. Informational [Page 12] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: Max-Forwards: 69 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844528 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=sendonly /* A replies with normal SDP */ F12 200 OK A -> Proxy 1 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F13 200 OK Proxy 1 -> B SIP/2.0 200 OK Johnston, et al. Informational [Page 13] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F14 ACK B -> Proxy 1 ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 1 ACK Content-Length: 0 F15 ACK Proxy 1 -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Max-Forwards: 69 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 1 ACK Content-Length: 0 /* User B takes the call off hold */ F16 INVITE B -> Proxy 1 INVITE sip:UserA@client.here.com SIP/2.0 Johnston, et al. Informational [Page 14] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844529 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F17 INVITE Proxy 1 -> A INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: Max-Forwards: 69 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844529 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F18 200 OK A -> Proxy 1 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Johnston, et al. Informational [Page 15] Internet Draft SIP Service Examples November 2002 Record-Route: From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F19 200 OK Proxy 1 -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F20 ACK B -> Proxy 1 ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 2 ACK Content-Length: 0 Johnston, et al. Informational [Page 16] Internet Draft SIP Service Examples November 2002 F21 ACK Proxy 1 -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Max-Forwards: 69 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 2 ACK Content-Length: 0 /* RTP Media stream re-established. User A disconnects. */ F22 BYE A -> Proxy 1 BYE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 2 BYE Content-Length: 0 F23 BYE Proxy 1 -> B BYE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 2 BYE Content-Length: 0 F24 200 OK B -> Proxy 1 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Johnston, et al. Informational [Page 17] Internet Draft SIP Service Examples November 2002 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 2 BYE Content-Length: 0 F25 200 OK Proxy 1 -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 2 BYE Content-Length: 0 Johnston, et al. Informational [Page 18] Internet Draft SIP Service Examples November 2002 2.2 Consultation Hold User A Proxy User B User C | | | | | INVITE F1 | | | |--------------->| INVITE F2 | | | |------------->| | |(100 Trying) F3 | | | |<---------------|180 Ringing F4| | | |<-------------| | | 180 Ringing F5 | | | |<---------------| 200 OK F6 | | | |<-------------| | | 200 OK F7 | | | |<---------------| | | | ACK F8 | | | |--------------->| ACK F9 | | | |------------->| | | Both way RTP Established | | |<=============================>| | | |INVITE(hold) F10 | |INVITE(hold) F11|<-------------| | |<---------------| | | | 200 OK F12 | | | |--------------->| 200 OK F13 | | | |------------->| | | | ACK F14 | | | |<-------------| | | ACK F15 | | | |<---------------| | | | No RTP Sent! | | | | INVITE F16 | | | |<-------------| | | | | INVITE F17 | | |--------------------------------->| | |(100 Trying) F18 | | |------------->| | | | | 180 Ringing F19 | | |<---------------------------------| | | 180 Ringing F20 | | |------------->| | | | | 200 OK F21 | | |<---------------------------------| | | 200 OK F22 | | | |------------->| | | | ACK F23 | | | |<-------------| | | | | ACK F24 | | |--------------------------------->| | | Both way RTP Established | Johnston, et al. Informational [Page 19] Internet Draft SIP Service Examples November 2002 | | |<=================>| | | BYE F25 | | | |<-------------| | | | | BYE F26 | | |--------------------------------->| | | | 200 OK F27 | | |<---------------------------------| | | 200 OK F28 | | | |------------->| | | | INVITE F29 | | | INVITE F30 |<-------------| | |<---------------| | | | 200 OK F31 | | | |--------------->| 200 OK F32 | | | |------------->| | | | ACK F33 | | | |<-------------| | | ACK F34 | | | |<---------------| | | | Both way RTP Established | | |<=============================>| | | BYE F35 | | | |--------------->| BYE F36 | | | |------------->| | | | 200 OK F37 | | | |<-------------| | | 200 OK F38 | | | |<---------------| | | | | | | User A calls user B. User B places call on hold. User B calls User C. User B then disconnects with C, then takes the call with User A off hold. The call ends with B hangs up. Message Details F1 INVITE A -> Proxy 1 INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com Johnston, et al. Informational [Page 20] Internet Draft SIP Service Examples November 2002 s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 INVITE Proxy 1 -> B INVITE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F3(100 Trying) Proxy 1 -> A SIP/2.0 100 Trying Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F4 180 Ringing B -> Proxy 1 SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Johnston, et al. Informational [Page 21] Internet Draft SIP Service Examples November 2002 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content Length:0 F5 180 Ringing Proxy 1 -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content Length: 0 F6 200 OK B -> Proxy 1 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F7 200 OK Proxy 1 -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Johnston, et al. Informational [Page 22] Internet Draft SIP Service Examples November 2002 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F8 ACK A -> Proxy 1 ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F9 ACK Proxy 1 -> B ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* User B places User A on hold. */ F10 INVITE B -> Proxy 1 INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Johnston, et al. Informational [Page 23] Internet Draft SIP Service Examples November 2002 Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844528 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=sendonly F11 INVITE Proxy 1 -> A INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: Max-Forwards: 69 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844528 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=sendonly F12 200 OK A -> Proxy 1 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Johnston, et al. Informational [Page 24] Internet Draft SIP Service Examples November 2002 Record-Route: From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F13 200 OK Proxy 1 -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F14 ACK B -> Proxy 1 ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 Johnston, et al. Informational [Page 25] Internet Draft SIP Service Examples November 2002 F15 ACK Proxy 1 -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Max-Forwards: 69 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F16 INVITE B -> Proxy 1 INVITE sip:UserC@anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy Call-ID: 9876543210@there.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844834 2890844834 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 50170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F17 INVITE Proxy 1 -> C INVITE sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: Max-Forwards: 69 From: LittleGuy ;tag=8675309 To: OtherGuy Call-ID: 9876543210@there.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Johnston, et al. Informational [Page 26] Internet Draft SIP Service Examples November 2002 Content-Length: ... v=0 o=UserB 2890844834 2890844834 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 50170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F18 (100 Trying) Proxy 1 -> B SIP/2.0 100 Trying Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: LittleGuy ;tag=8675309 To: OtherGuy Call-ID: 9876543210@there.com CSeq: 1 INVITE Content-Length: 0 F19 180 Ringing C -> Proxy 1 SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=456654 Call-ID: 9876543210@here.com CSeq: 1 INVITE Contact: Content Length:0 F20 180 Ringing Proxy 1 -> B SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=client.anywhere.com Record-Route: From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=456654 Call-ID: 9876543210@there.com CSeq: 1 INVITE Contact: Content Length: 0 Johnston, et al. Informational [Page 27] Internet Draft SIP Service Examples November 2002 F21 200 OK C -> Proxy 1 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=456654 Call-ID: 9876543210@there.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserC 2890844922 2890844922 IN IP4 client.anywhere.com s=Session SDP c=IN IP4 client.anywhere.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F22 200 OK Proxy 1 -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=456654 Call-ID: 9876543210@there.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserC 2890844922 2890844922 IN IP4 client.anywhere.com s=Session SDP c=IN IP4 client.anywhere.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F23 ACK B -> Proxy 1 ACK sip:UserC@client.anywhere.com SIP/2.0 Johnston, et al. Informational [Page 28] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=456654 Call-ID: 9876543210@there.com CSeq: 1 ACK Content-Length: 0 F24 ACK Proxy 1 -> C ACK sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Max-Forwards: 69 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=456654 Call-ID: 9876543210@there.com CSeq: 1 ACK Content-Length: 0 F25 BYE B -> Proxy 1 BYE sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=456654 Call-ID: 9876543210@there.com CSeq: 2 BYE Content-Length: 0 F26 BYE Proxy 1 -> C BYE sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Max-Forwards: 69 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=456654 Call-ID: 9876543210@there.com CSeq: 2 BYE Content-Length: 0 F27 200 OK C -> Proxy 1 Johnston, et al. Informational [Page 29] Internet Draft SIP Service Examples November 2002 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=456654 Call-ID: 9876543210@there.com CSeq: 2 BYE Content-Length: 0 F28 200 OK Proxy 1 -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=456654 Call-ID: 9876543210@there.com CSeq: 2 BYE Content-Length: 0 /* User B takes the call off hold */ F29 INVITE B -> Proxy 1 INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844529 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F30 INVITE Proxy 1 -> A Johnston, et al. Informational [Page 30] Internet Draft SIP Service Examples November 2002 INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: Max-Forwards: 69 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844529 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F31 200 OK A -> Proxy 1 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Record-Route: From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F32 200 OK Proxy 1 -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Johnston, et al. Informational [Page 31] Internet Draft SIP Service Examples November 2002 ;received=192.0.2.105 Record-Route: From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F33 ACK B -> Proxy 1 ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 2 ACK Content-Length: 0 F34 ACK Proxy 1 -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Max-Forwards: 69 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 2 ACK Content-Length: 0 F35 BYE A -> Proxy 1 BYE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 Johnston, et al. Informational [Page 32] Internet Draft SIP Service Examples November 2002 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F36 BYE Proxy 1 -> B BYE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F37 200 OK B -> Proxy 1 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F38 200 OK Proxy 1 -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 Johnston, et al. Informational [Page 33] Internet Draft SIP Service Examples November 2002 2.3 Music On Hold User A User B Music Server | | | | INVITE F1 | | |--------------->| | | 180 Ringing F2 | | |<---------------| | | 200 OK F3 | | |<---------------| | | ACK F4 | | |--------------->| | | RTP | | |<==============>| | | | | | B places A on hold with music | | | | | | INVITE no sdp F5 | |------------->| | |200 OK sdpM F6| | |<-------------| |INVITE (hold) F7| | |<---------------| | | 200 OK sdpA F8 | | |--------------->| | | ACK F9 | | |<---------------| | | | ACK sdpA F10 | | |------------->| | RTP | |<==============================| | | | | B Picks up the Call | | | BYE F11 | | |------------->| | | 200 OK F12 | | |<-------------| | INVITE F13 | | |<---------------| | | 200 OK F14 | | |--------------->| | | ACK F15 | | |<---------------| | | RTP | | |<==============>| | In this flow,B places A on hold with music. This is performed by B acting as a B2BUA (Back-to-Back User Agent) using 3pcc (third party call control) [7] to INVITE a Music Server into the session, which Johnston, et al. Informational [Page 34] Internet Draft SIP Service Examples November 2002 sends RTP music to A. B picks the call up from hold by sending a BYE to the music server and taking A off of hold. Note that if A responds to the INVITE with hold SDP with hold SDP in the 200 OK, this call flow will not work properly. Note also that A will receive RTP packets from two different IP addresses during this call flow. Message Details F1 INVITE A -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 180 Ringing B -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F3 200 OK B -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Johnston, et al. Informational [Page 35] Internet Draft SIP Service Examples November 2002 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F4 ACK A -> B ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* User B places A on hold with music by acting as a B2BUA and sending an INVITE to the Music Server */ F5 INVITE B -> Music Server INVITE sip:music@server.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: Music Call-ID: sdjfdjfskdf@there.com CSeq: 1 INVITE Contact: Content-Length: 0 F6 200 OK C -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: LittleGuy ;tag=8675309 Johnston, et al. Informational [Page 36] Internet Draft SIP Service Examples November 2002 To: Music ;tag=90210 Call-ID: sdjfdjfskdf@there.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=MusicServer 2890844576 2890844577 IN IP4 music.server.com s=Session SDP c=IN IP4 music.server.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=sendonly /* B re-INVITEs A on hold */ F7 INVITE B -> A INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 To: BigGuy ;tag=1234567 Max-Forwards: 70 From: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844528 IN IP4 music.server.com s=Session SDP c=IN IP4 music.server.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=sendonly /* A responds with normal SDP */ F8 200 OK A -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 To: BigGuy ;tag=1234567 From: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 INVITE Johnston, et al. Informational [Page 37] Internet Draft SIP Service Examples November 2002 Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F9 ACK B -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 To: BigGuy ;tag=1234567 Max-Forwards: 70 From: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* B passes SDP of A to the Music Server to allow music to be sent from B to A */ F10 ACK B -> Music Server ACK sip:music@server.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: Music ;tag=90210 Call-ID: sdjfdjfskdf@there.com CSeq: 1 ACK Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 /* RTP music is now sent from the Music Server to A */ /* B picks up the call from the Music Server */ Johnston, et al. Informational [Page 38] Internet Draft SIP Service Examples November 2002 F11 BYE B -> Music Server BYE sip:music@server.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: Music ;tag=90210 Call-ID: sdjfdjfskdf@there.com CSeq: 2 BYE Content-Length: 0 F12 200 OK Music Server -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: LittleGuy ;tag=8675309 To: Music ;tag=90210 Call-ID: sdjfdjfskdf@there.com CSeq: 2 BYE Content-Length:0 /* B re-INVITEs taking A off hold */ F13 INVITE B -> A INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 To: BigGuy ;tag=1234567 Max-Forwards: 70 From: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844529 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F14 200 OK A -> B SIP/2.0 200 OK Johnston, et al. Informational [Page 39] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 To: BigGuy ;tag=1234567 From: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F15 ACK B -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 To: BigGuy ;tag=1234567 Max-Forwards: 70 From: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 2 ACK Content-Length: 0 /* Normal media session between A and B is resumed */ Johnston, et al. Informational [Page 40] Internet Draft SIP Service Examples November 2002 2.4 Unattended Transfer User A User B User C | INVITE F1 | | |<-------------------| | | 180 Ringing F2 | | |------------------->| | | 200 OK F3 | | |------------------->| | | ACK F4 | | |<-------------------| | | RTP | | |<==================>| | | | | | A performs unattended transfer | | | | | REFER Refer-To:C F5| | |------------------->| | | 202 Accepted F6 | | |<-------------------| | | NOTIFY F7 | | |<-------------------| | | 200 OK F8 | | |------------------->| | | BYE F9 | | |------------------->| | | 200 OK F10 | | |<-------------------| | | No RTP Session | INVITE Referred-By: A F11 | |------------------->| | | 180 Ringing F12 | | |<-------------------| | | 200 OK F13 | | |<-------------------| | | ACK F14 | | |------------------->| | | RTP | | |<==================>| | NOTIFY F14 | | |<-------------------| | | 200 OK F15 | | |------------------->| | | | | User B call User A. User A then transfers User B to User C, then User A disconnects with User B. User B establishes the session to C then reports the success back to A in the NOTIFY. If the transfer fails, User B can send a new INVITE back to A to re-establish the session. Johnston, et al. Informational [Page 41] Internet Draft SIP Service Examples November 2002 Note that the BYE could be sent by A after the NOTIFY. Also, if A has flushed all state information, the NOTIFY may receive a 481 Call Leg Does Not Exist. Message Details F1 INVITE B -> A INVITE sip:UserA@here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 180 Ringing A -> B SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F3 200 OK A -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Johnston, et al. Informational [Page 42] Internet Draft SIP Service Examples November 2002 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F4 ACK B -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 1 ACK Content-Length: 0 /* Session is established between A and B. */ /* A peforms unattended transfer of B to C */ F5 REFER A -> B REFER sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 2 REFER Refer-To: Referred-By: Contact: Content-Length: 0 F6 202 Accepted B -> A SIP/2.0 202 Accepted Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Johnston, et al. Informational [Page 43] Internet Draft SIP Service Examples November 2002 ;received=192.0.2.113 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 2 REFER Content-Length: 0 F7 NOTIFY B -> A NOTIFY sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 2 NOTIFY Event: refer Subscription-State: active;expires=60 Content-Type: message/sipfrag Content-Length: ... SIP/2.0 100 Trying F8 200 OK A -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 2 NOTIFY Content-Length: 0 /* A now disconnects with B */ F9 BYE A -> B BYE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 3 BYE Content-Length: 0 Johnston, et al. Informational [Page 44] Internet Draft SIP Service Examples November 2002 F10 200 OK B -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 3 BYE Content-Length: 0 /* B attempts the transfer to C */ F11 INVITE B -> C INVITE sip:UserC@anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy Call-ID: 7436222@here.com CSeq: 1 INVITE Contact: Referred-By: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844539 2890844539 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423821 0 m=audio 3458 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F12 180 Ringing C -> B SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=928287 Call-ID: 7436222@here.com CSeq: 1 INVITE Contact: Content-Length: 0 Johnston, et al. Informational [Page 45] Internet Draft SIP Service Examples November 2002 F13 200 OK C -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=928287 Call-ID: 7436222@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserC 2890844527 2890844527 IN IP4 client.anywhere.com s=Session SDP c=IN IP4 client.anywhere.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F14 ACK B -> C ACK sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=928287 Call-ID: 7436222@here.com CSeq: 1 ACK Content-Length: 0 /* B and C now have established a session. B reports success to A which A probably ignores. */ F15 NOTIFY B -> A NOTIFY sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 3 NOTIFY Event: refer Subscription-State: terminated;reason=noresource Content-Type: message/sipfrag Content-Length: ... Johnston, et al. Informational [Page 46] Internet Draft SIP Service Examples November 2002 SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=928287 Call-ID: 7436222@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... F16 200 OK A -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=314159 To: BigGuy ;tag=1234567 Call-ID: 12345601@here.com CSeq: 3 NOTIFY Content-Length: 0 Johnston, et al. Informational [Page 47] Internet Draft SIP Service Examples November 2002 2.5 Attended Transfer User A User B User C | | | | INVITE F1 | | |--------------->| | | 180 Ringing F2 | | |<---------------| | | 200 OK F3 | | |<---------------| | | ACK F4 | | |--------------->| | | RTP | | |<==============>| | |INVITE (hold) F5| | |<---------------| | | 200 OK F6 | | |--------------->| | | ACK F7 | | |<---------------| | | No RTP | | | | INVITE F8 | | |------------->| | | 180 Ringing F9 | |<-------------| | | 200 OK F10 | | |<-------------| | | ACK F11 | | |------------->| | | RTP | | |<============>| | |INVITE (hold) F12 | |------------->| | | 200 OK F13 | | |<-------------| | | ACK F14 | | |------------->| | | No RTP | | REFER Refer-To: C F15 | |<---------------| | |202 Accepted F16| | |--------------->| | | NOTIFY F17 | | |--------------->| | | 200 OK F18 | | |<---------------| | | INVITE Replaces: B F19 | |------------------------------>| | 200 OK F20 | |<------------------------------| | ACK F21 | Johnston, et al. Informational [Page 48] Internet Draft SIP Service Examples November 2002 |------------------------------>| | RTP | |<=============================>| | | BYE F22 | | |<-------------| | | 200 OK F23 | | |------------->| | NOTIFY F24 | | |--------------->| | | 200 OK F25 | | |<---------------| | | BYE F26 | | |<---------------| | | 200 OK F27 | | |--------------->| | User A calls User B. User B puts User A on hold then calls User C to announce transfer, then places C on hold. User B transfers User A to User C which replaces the session between B and C. C then disconnects session with B. A reports success of transfer to B, who then disconnects with A. In this example, the Replaces header [5] is inserted into the Refer-To URL by B. Note that the Refer-To URI is the Contact URI returned by C in the 200 OK response F10. This ensures that only the correct instance of User C is reached. If the triggered INVITE had failed, B would have retried the REFER with a Refer-To URI of the URI used to reach User C but with a Require: replaces header escaped in the Refer-To header field, as discussed in [9]. Message Details F1 INVITE A -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 Johnston, et al. Informational [Page 49] Internet Draft SIP Service Examples November 2002 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 180 Ringing B -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F3 200 OK B -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F4 ACK A -> B ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 Johnston, et al. Informational [Page 50] Internet Draft SIP Service Examples November 2002 /* User A and User B have established a session. User B puts User A on Hold */ F5 INVITE B -> A INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1024 INVITE Contact: Content-Type: application/sdp Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Length: ... v=0 o=UserB 2890844527 2890844528 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=sendonly F6 200 OK A -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1024 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 Johnston, et al. Informational [Page 51] Internet Draft SIP Service Examples November 2002 F7 ACK B -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1024 ACK Content-Length: 0 /* User B calls User C */ F8 INVITE B -> C INVITE sip:UserC@anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy Call-ID: sdjfdjfskdf@there.com CSeq: 42 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserB 28908445834 2890844834 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423645 0 m=audio 3458 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F9 180 Ringing C -> B SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=5f35a3 Call-ID: sdjfdjfskdf@there.com CSeq: 42 INVITE Contact: Content-Length: 0 Johnston, et al. Informational [Page 52] Internet Draft SIP Service Examples November 2002 F10 200 OK C -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=5f35a3 Call-ID: sdjfdjfskdf@there.com CSeq: 42 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserC 2890844922 2890844922 IN IP4 client.anywhere.com s=Session SDP c=IN IP4 client.anywhere.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F11 ACK B -> C ACK sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=5f35a3 Call-ID: sdjfdjfskdf@there.com CSeq: 42 ACK Content-Length: 0 /* User B puts User C on hold */ F12 INVITE B -> C INVITE sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=5f35a3 Call-ID: sdjfdjfskdf@there.com CSeq: 43 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... Johnston, et al. Informational [Page 53] Internet Draft SIP Service Examples November 2002 v=0 o=UserB 289084834 2890844835 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423645 0 m=audio 3458 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=sendonly F13 200 OK C -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=5f35a3 Call-ID: sdjfdjfskdf@there.com CSeq: 43 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserC 2890844922 2890844922 IN IP4 client.anywhere.com s=Session SDP c=IN IP4 client.anywhere.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F14 ACK B -> C ACK sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=5f35a3 Call-ID: sdjfdjfskdf@there.com CSeq: 43 ACK Content-Length: 0 /* User B Transfers User A to User C. */ F15 REFER B -> A REFER sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Johnston, et al. Informational [Page 54] Internet Draft SIP Service Examples November 2002 Max-Forwards: 70 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345678900@here.com CSeq: 1025 REFER Refer-To: Referred-By: Contact: Content-Length: 0 F16 202 Accepted A -> B SIP/2.0 202 Accepted Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=1234567 To: BigGuy ;tag=23431 Call-ID: 12345678900@here.com CSeq: 1025 REFER Content-Length: 0 F17 NOTIFY A -> B NOTIFY sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345678900@here.com CSeq: 2 NOTIFY Event: refer Subscription-State: active;expires=60 Content-Type: message/sipfrag Content-Length: ... SIP/2.0 100 Trying F18 200 OK B -> C SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 To: LittleGuy ;tag=1234567 From: OtherGuy ;tag=5f35a3 Call-ID: 12345678900@here.com CSeq: 2 NOTIFY Content-Length: 0 Johnston, et al. Informational [Page 55] Internet Draft SIP Service Examples November 2002 /* User A establishes session with User C which replaces the session between User B and User C */ F19 INVITE A -> C INVITE sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.anywhere.com:5060;branch=z9hG4bKadfe4ko To: OtherGuy Max-Forwards: 70 From: BigGuy ;tag=3461 Call-ID: 9435674543@here.com CSeq: 1 INVITE Referred-By: Replaces: 12345600@here.com;to-tag=23431;from-tag=8675309 Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844989 2890844989 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423643 0 m=audio 3458 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F20 200 OK C -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.anywhere.com:5060;branch=z9hG4bKadfe4ko ;received=192.0.2.123 To: OtherGuy ;tag=ff3a From: BigGuy ;tag=3461 Call-ID: 9435674543@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844221 2890844221 IN IP4 client.anywhere.com s=Session SDP c=IN IP4 client.anywhere.com t=3034423452 0 m=audio 49172 RTP/AVP 0 a=rtpmap:0 PCMU/8000 Johnston, et al. Informational [Page 56] Internet Draft SIP Service Examples November 2002 F21 ACK A -> C ACK sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.anywhere.com:5060;branch=z9hG4bKadfe4ko To: OtherGuy ;tag=ff3a Max-Forwards: 70 From: BigGuy ;tag=3461 Call-ID: 9435674543@here.com CSeq: 1 INVITE Content-Length: 0 /* User C then disconnects from User B */ F22 BYE C -> B BYE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 To: LittleGuy ;tag=8675309 Max-Forwards: 70 From: OtherGuy ;tag=5f35a3 Call-ID: sdjfdjfskdf@there.com CSeq: 1 BYE Content-Length: 0 F23 200 OK B -> C SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 To: LittleGuy ;tag=8675309 From: OtherGuy ;tag=5f35a3 Call-ID: sdjfdjfskdf@there.com CSeq: 1 BYE Content-Length: 0 /* User A tells User B that the call has been successfully transferred */ F24 NOTIFY A -> B NOTIFY sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345678900@here.com CSeq: 3 NOTIFY Johnston, et al. Informational [Page 57] Internet Draft SIP Service Examples November 2002 Event: refer Subscription-State: terminated;reason=noresource Content-Type: message/sipfrag Content-Length: ... SIP/2.0 200 OK Via: SIP/2.0/UDP client.anywhere.com:5060;branch=z9hG4bKadfe4ko ;received=192.0.2.123 From: OtherGuy ;tag=ff3a To: BigGuy ;tag=3461 Call-ID: 9435674543@anywhere.com CSeq: 1 INVITE Contact: F25 200 OK B -> C SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 To: LittleGuy ;tag=1234567 From: OtherGuy ;tag=5f35a3 Call-ID: 12345678900@here.com CSeq: 3 NOTIFY Content-Length: 0 /* User B disconnects with User A */ F26 BYE B -> A BYE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345678900@here.com CSeq: 1026 BYE Content-Length: 0 F27 200 OK A -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345678900@here.com CSeq: 1026 BYE Content-Length: 0 Johnston, et al. Informational [Page 58] Internet Draft SIP Service Examples November 2002 2.6 Call Forwarding Unconditional User A Proxy Gateway | | | | INVITE F1 | | |--------------->| INVITE F2 | |(100 Trying) F3 |------------->| |<---------------|180 Ringing F4| | 180 Ringing F5 |<-------------| |<---------------| 200 OK F6 | | 200 OK F7 |<-------------| |<---------------| | | ACK F8 | | |--------------->| ACK F9 | | |------------->| | Both way RTP Established | |<=============================>| | BYE F10 | | |--------------->| BYE F11 | | |------------->| | | 200 OK F12 | | 200 OK F13 |<-------------| |<---------------| | | | | User B wants all calls forwarded to the PSTN. User A calls User B. The Proxy server rewrites the request URI, and forwards the INVITE to a Gateway. Details of messaging behind the Gateway are not shown. Message Details F1 INVITE A -> Proxy INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com Johnston, et al. Informational [Page 59] Internet Draft SIP Service Examples November 2002 t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 /* Proxy forwards call by rewriting Request-URI */ F2 INVITE Proxy -> Gateway INVITE sip:+19727293660@gw1.wcom.com;user=phone SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F3 (100 Trying) Proxy -> A SIP/2.0 100 Trying Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F4 180 Ringing Gateway -> Proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Johnston, et al. Informational [Page 60] Internet Draft SIP Service Examples November 2002 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content Length:0 F5 180 Ringing Proxy -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content Length: 0 F6 200 OK Gateway -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=GATEWAY1 2890844527 2890844527 IN IP4 gatewayone.wcom.com s=Session SDP c=IN IP4 gatewayone.wcom.com t=0 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F7 200 OK Proxy -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Johnston, et al. Informational [Page 61] Internet Draft SIP Service Examples November 2002 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=GATEWAY1 2890844527 2890844527 IN IP4 gatewayone.wcom.com s=Session SDP c=IN IP4 gatewayone.wcom.com t=0 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F8 ACK A -> Proxy ACK sip:+19727293660@gw1.wcom.com;user=phone SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F9 ACK Proxy -> Gateway ACK sip:+19727293660@gw1.wcom.com;user=phone SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F10 BYE A -> Proxy 1 BYE sip:+19727293660@gw1.wcom.com;user=phone SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 From: BigGuy ;tag=1234567 Johnston, et al. Informational [Page 62] Internet Draft SIP Service Examples November 2002 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F11 BYE Proxy 1 -> Gateway BYE sip:+19727293660@gw1.wcom.com;user=phone SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F12 200 OK Gateway -> Proxy 1 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F13 200 OK Proxy 1 -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 Johnston, et al. Informational [Page 63] Internet Draft SIP Service Examples November 2002 2.7 Call Forwarding - Busy User A Proxy User B1 User B2 | | | | | INVITE F1 | | | |--------------->| INVITE F2 | | | |------------->| | |(100 Trying) F3 | | | |<---------------| 486 Busy F4 | | | |<-------------| | | | ACK F5 | | | |------------->| | | | | INVITE F6 | | |--------------------------------->| | | | 180 Ringing F7 | | |<---------------------------------| | 180 Ringing F8 | | | |<---------------| | 200 OK F9 | | |<---------------------------------| | 200 OK F10 | | | |<---------------| | | | ACK F11 | | | |--------------->| | ACK F12 | | |--------------------------------->| | Both way RTP Established | |<=================================================>| | BYE F13 | | | |--------------->| | BYE F14 | | |--------------------------------->| | | | 200 OK F15 | | 200 OK F16 |<---------------------------------| |<---------------| | | | | | | User B wants calls to B1 forwarded to B2 if B1 is busy (this information is known to the proxy). User A calls B1, B1 is busy, the proxy server places call to B2. Message Details F1 INVITE A -> Proxy INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Johnston, et al. Informational [Page 64] Internet Draft SIP Service Examples November 2002 Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 INVITE Proxy -> B1 INVITE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F3 (100 Trying) Proxy -> A SIP/2.0 100 Trying Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F4 486 Busy Here B1 -> Proxy SIP/2.0 486 Busy Here Johnston, et al. Informational [Page 65] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F5 ACK Proxy -> B1 ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* The proxy now forwards the call to B2 */ F6 INVITE Proxy -> B2 INVITE sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F7 180 Ringing B2 -> Proxy Johnston, et al. Informational [Page 66] Internet Draft SIP Service Examples November 2002 SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F8 180 Ringing Proxy -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F9 200 OK B2 -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client2.there.com s=Session SDP c=IN IP4 client2.there.com t=0 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 Johnston, et al. Informational [Page 67] Internet Draft SIP Service Examples November 2002 F10 200 OK Proxy -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client2.there.com s=Session SDP c=IN IP4 client2.there.com t=0 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F11 ACK A -> Proxy ACK sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F12 ACK Proxy -> B2 ACK sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* RTP streams are established between A and B2 */ Johnston, et al. Informational [Page 68] Internet Draft SIP Service Examples November 2002 /* User A eventually hangs up with User B2. */ F13 BYE A -> Proxy BYE sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F14 BYE Proxy -> B2 BYE sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F15 200 OK B2 -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F16 200 OK Proxy -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com Johnston, et al. Informational [Page 69] Internet Draft SIP Service Examples November 2002 CSeq: 2 BYE Content-Length: 0 Johnston, et al. Informational [Page 70] Internet Draft SIP Service Examples November 2002 2.8 Call Forwarding - No Answer User A Proxy User B1 User B2 | | | | | INVITE F1 | | | |--------------->| INVITE F2 | | |(100 Trying) F3 |------------->| | |<---------------|180 Ringing F4| | | 180 Ringing F5 |<-------------| | |<---------------| | | | Request Timeout | | | | | | | CANCEL F6 | | | |------------->| | | | 200 OK F7 | | | |<-------------| | | | 487 F8 | | | |<-------------| | | | ACK F9 | | | |------------->| | | | | INVITE F10 | | |--------------------------------->| | | | 180 Ringing F11 | | 180 Ringing F12|<---------------------------------| |<---------------| | 200 OK F13 | | |<---------------------------------| | 200 OK F14 | | | |<---------------| | | | ACK F15 | | | |--------------->| | ACK F16 | | |--------------------------------->| | Both way RTP Established | |<=================================================>| | BYE F17 | | | |--------------->| | BYE F18 | | |--------------------------------->| | | | 200 OK F19 | | 200 OK F20 |<---------------------------------| |<---------------| | | | | | | User B wants calls to B1 forwarded to B2 if B1 is not answered (information is known to the proxy server). User A calls B1 and no one answers. The proxy server then places the call to B2. Message Details F1 INVITE A -> Proxy INVITE sip:UserB@there.com SIP/2.0 Johnston, et al. Informational [Page 71] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 INVITE Proxy -> B1 INVITE sip:UserB1@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F3 (100 Trying) Proxy -> A SIP/2.0 100 Trying Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com Johnston, et al. Informational [Page 72] Internet Draft SIP Service Examples November 2002 CSeq: 1 INVITE Content-Length: 0 F4 180 Ringing B1 -> Proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=3145678 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F5 180 Ringing Proxy -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=3145678 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 /* B1 rings until a configurable timer expires in the Proxy. The Proxy sends Cancel and proceeds down the list of routes. */ F6 CANCEL Proxy -> B1 CANCEL sip:UserB1@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Max-Forwards: 70 From: BigGuy To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 CANCEL Content-Length: 0 F7 200 OK B1 -> Proxy SIP/2.0 200 OK Johnston, et al. Informational [Page 73] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 From: BigGuy To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 CANCEL Content-Length: 0 F8 487 Request Terminated B1 -> Proxy SIP/2.0 487 Request Terminated Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=3145678 Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F9 ACK Proxy -> B1 ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=3145678 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F10 INVITE Proxy -> B2 INVITE sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 Johnston, et al. Informational [Page 74] Internet Draft SIP Service Examples November 2002 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F11 180 Ringing B2 -> Proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F12 180 Proxy -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F13 200 OK B2 -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Johnston, et al. Informational [Page 75] Internet Draft SIP Service Examples November 2002 Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client2.there.com s=Session SDP c=IN IP4 client2.there.com t=0 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F14 200 OK Proxy -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client2.there.com s=Session SDP c=IN IP4 client2.there.com t=0 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F15 ACK A -> Proxy ACK sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F16 ACK Proxy -> B2 ACK sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Johnston, et al. Informational [Page 76] Internet Draft SIP Service Examples November 2002 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* RTP streams are established between A and B2. User A Hangs Up with User B2. */ F17 BYE A -> Proxy BYE sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F18 BYE Proxy -> B2 BYE sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 F19 200 OK B2 -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 Johnston, et al. Informational [Page 77] Internet Draft SIP Service Examples November 2002 F20 200 OK Proxy -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 2 BYE Content-Length: 0 Johnston, et al. Informational [Page 78] Internet Draft SIP Service Examples November 2002 2.9 3-way Conference û Third Party is Added User A User B User C | INVITE F1 | | |--------------->| | | 180 Ringing F2 | | |<---------------| | | 200 OK F3 | | |<---------------| | | ACK F4 | | |--------------->| | | RTP | | |<==============>| | | INVITE F5 | | |<---------------| | | 200 OK F6 | | |--------------->| | | ACK F7 | | |<---------------| INVITE F8 | | |------------->| | | 180 F9 | | |<-------------| | | 200 OK F10 | | |<-------------| | | ACK F11 | | |------------->| | | RTP | | |<============>| In this scenario, A and B are in a 2-party call (session) when B wishes to add C into the conversation. B is capable of media mixing in a 3-party call. B first sends a re-INVITE to A changing Contact URIs to one that indicates A's mixer. B then INVITEs C using the same Contact URI. Message Details F1 INVITE A -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Johnston, et al. Informational [Page 79] Internet Draft SIP Service Examples November 2002 Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 180 Ringing B -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F3 200 OK B -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F4 ACK A -> B Johnston, et al. Informational [Page 80] Internet Draft SIP Service Examples November 2002 ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* User A and User B have established a session. User B re-INVITEs changing Contact URIs */ F5 INVITE B -> A INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1024 INVITE Contact: Content-Type: application/sdp Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Length: ... v=0 o=UserB 2890844527 2890844528 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 49172 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=sendonly F6 200 OK A -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1024 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Johnston, et al. Informational [Page 81] Internet Draft SIP Service Examples November 2002 Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F7 ACK B -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1024 ACK Content-Length: 0 /* User B calls C */ F8 INVITE B -> C INVITE sip:UserC@anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy Call-ID: sdjfdjfskdf@there.com CSeq: 42 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserB 28908445834 2890844834 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423645 0 m=audio 48174 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F9 180 Ringing C -> B SIP/2.0 200 OK Johnston, et al. Informational [Page 82] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=341313 Call-ID: sdjfdjfskdf@there.com CSeq: 42 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Length: 0 F10 200 OK C -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=341313 Call-ID: sdjfdjfskdf@there.com CSeq: 42 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserC 2890844922 2890844922 IN IP4 client.anywhere.com s=Session SDP c=IN IP4 client.anywhere.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F11 ACK B -> C ACK sip:UserC@client.anywhere.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: OtherGuy ;tag=341313 Call-ID: sdjfdjfskdf@there.com CSeq: 42 ACK Content-Length: 0 /* User B's mixer know mixes media from both A and C to create the 3- way conference. */ Johnston, et al. Informational [Page 83] Internet Draft SIP Service Examples November 2002 2.10 3-way Conference û Third Party Joins User A User B User C | INVITE F1 | | |--------------->| | | 180 Ringing F2 | | |<---------------| | | 200 OK F3 | | |<---------------| | | ACK F4 | | |--------------->| | | RTP | | |<==============>| INVITE Join:A-B F5 | |<-------------| | | 180 F6 | | |------------->| | INVITE F7 | | |<---------------| | | 200 OK F8 | | |--------------->| | | ACK F9 | | |<---------------| | | | 200 OK F10 | | |------------->| | | ACK F11 | | |<-------------| | | RTP | | |<============>| In this scenario, A and B are in a 2 party call and C wishes to join resulting in a three party call. C could have learned BÆs conference URI using some non-SIP means, or possibly from a NOTIFY with the dialog package sent by B. C sends an INVITE to B containing a Join header identifying the dialog between A and B. B re-INVITEs A to switch to B's mixer then accepts the INVITE from C, resulting in the 3-way call. Message Details F1 INVITE A -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Johnston, et al. Informational [Page 84] Internet Draft SIP Service Examples November 2002 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 180 Ringing B -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F3 200 OK B -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces, join Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 Johnston, et al. Informational [Page 85] Internet Draft SIP Service Examples November 2002 F4 ACK A -> B ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=23431 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* User A and User B have established a session. User C requests to join the session */ F5 INVITE C -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.anywhere.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: OtherGuy ;tag=8675309 To: LittleGuy Call-ID: 452k499sk@anywhere.com CSeq: 99 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces, join Join: 12345600@here.com;from-tag=1234567;to-tag=23431 Content-Type: application/sdp Content-Length: ... v=0 o=UserC 2890844922 2890844922 IN IP4 client.anywhere.com s=Session SDP c=IN IP4 client.anywhere.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F6 180 Ringing C -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.anywhere.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.120 From: OtherGuy ;tag=8675309 To: LittleGuy ;tag=0982 Call-ID: 452k499sk@anywhere.com Johnston, et al. Informational [Page 86] Internet Draft SIP Service Examples November 2002 CSeq: 99 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Length: 0 F7 INVITE B -> A INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1024 INVITE Contact: Content-Type: application/sdp Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Length: ... v=0 o=UserB 2890844527 2890844528 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 49172 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=sendonly F8 200 OK A -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.113 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1024 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 Johnston, et al. Informational [Page 87] Internet Draft SIP Service Examples November 2002 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F9 ACK B -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=23431 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1024 ACK Content-Length: 0 F10 200 OK C -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.anywhere.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.120 From: OtherGuy ;tag=8675309 To: LittleGuy ;tag=0982 Call-ID: 452k499sk@anywhere.com CSeq: 99 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserB 28908445834 2890844834 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423645 0 m=audio 48174 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F11 ACK OK B -> C ACK sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.anywhere.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: OtherGuy ;tag=8675309 To: LittleGuy ;tag=0982 Call-ID: 452k499sk@anywhere.com CSeq: 99 ACK Content-Length:0 Johnston, et al. Informational [Page 88] Internet Draft SIP Service Examples November 2002 2.11 Single Line Extension User A Forking Proxy User User User B1 B2 B3 | | | | | | INVITE F1 | | | | |--------------->| INVITE F2 | | | | |------------->| | | | | INVITE F3 | | | |-------------------->| | | | INVITE F4 | | | |--------------------------->| | 100 Trying F5 | | | | |<---------------|180 Ringing F6| | | | |<-------------| | | | 180 Ringing F7 | | | | |<---------------| | | | | | 480 Not Logged In F8| | | |<--------------------| | | | ACK F9 | | | |-------------------->| | | | 180 Ringing F10 | | 180 F11 |<---------------------------| |<---------------| 200 OK F12 | | 200 OK F13 |<---------------------------| |<---------------| | | | | | CANCEL 14 | | | | |------------->| | | | | 200 OK F15 | | | | |<-------------| | | | | 487 F16 | | | | |<-------------| | | | | ACK F17 | | | | |------------->| | | | ACK F18 | | | | |--------------->| ACK F19 | | | |--------------------------->| | Both way RTP Established | |<===========================================>| | | NOTIFY F20 | | |<---------------------------| | | NOTIFY F21 | | | | |------------->| | | | | NOTIFY F22 | | | |-------------------->| | | | NOTIFY F23 | | | |--------------------------->| | | 200 OK F24 | | | | |<-------------| | | | | 200 OK F25 | Johnston, et al. Informational [Page 89] Internet Draft SIP Service Examples November 2002 | |--------------------------->| | | 200 OK F26 | | | |<--------------------| | | | 482 Loop Detected F27 | | |<---------------------------| | | | | User B2 wants to join the call | | | | | | INVITE Join:A-B3 F28 | | |<--------------------| | | | INVITE Join: A-B3 F29 | | |------------->| | | | | INVITE Join: A-B3 F30 | | |-------------------->| | | | INVITE Join: A-B3 F31 | |--------------------------->| | | 100 Trying F32 | | | |-------------------->| | | | 481 Dialog Does Not Exist F33 | |<-------------| | | | | ACK F34 | | | | |------------->| | | | | 482 Loop Detected F35 | | |<--------------------| | | | ACK F36 | | | |-------------------->| | | | 200 OK F37 | | |<---------------------------| | | 200 OK F38 | | | |-------------------->| | | | |ACK F39 | | |----->| | | Both way RTP Established | | |<====>| B3 mixes RTP | | | | In Single Line Extension a call will ring several extensions at the same time (forking). The extension to answer the call becomes the active set. If other extensions pick up, the call becomes a conference call. In this flow, A calls B which results in the INVITE being forked to three devices, B1, B2, and B3. B3 answers the call and is connected to A. B3 sends a NOTIFY containing the dialog information to B, which is forked to B1 and B2. A user at B2 wishes to join the call and sends an INVITE with a Join header field to B to request this. This INVITE is forked and is accepted by B3 who then performs the mixing function. Note that if B3 is not capable of mixing the media, B3 would transfer both A and B2 to a conferencing bridge which would perform the mixing. Johnston, et al. Informational [Page 90] Internet Draft SIP Service Examples November 2002 The use of SUBSCRIBE and NOTIFY is defined in [11] while the dialog Event package is defined in [10]. Message Details F1 INVITE A -> Proxy INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t= 0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 INVITE Proxy -> B1 INVITE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t= 0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 Johnston, et al. Informational [Page 91] Internet Draft SIP Service Examples November 2002 F3 INVITE Proxy -> B2 INVITE sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F4 INVITE Proxy -> B3 INVITE sip:UserB3@client3.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.3 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 Johnston, et al. Informational [Page 92] Internet Draft SIP Service Examples November 2002 F5 100 Trying Proxy -> A SIP/2.0 100 Trying Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F6 180 Ringing B1 -> Proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F7 180 Ringing Proxy -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F8 480 Not Logged In B2 -> Proxy SIP/2.0 480 Not Logged In Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314756 Call-ID: 12345600@here.com CSeq: 1 INVITE Johnston, et al. Informational [Page 93] Internet Draft SIP Service Examples November 2002 Content-Length: 0 F9 ACK Proxy -> B2 ACK sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314756 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F10 180 Ringing B3 -> Proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=83749.3 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F11 180 Ringing B3 -> Proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F12 200 OK B3 -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=83749.3 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Johnston, et al. Informational [Page 94] Internet Draft SIP Service Examples November 2002 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client3.there.com s=Session SDP c=IN IP4 client3.there.com t=0 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F13 200 OK Proxy -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client3.there.com s=Session SDP c=IN IP4 client3.there.com t=0 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 /* Forking Proxy cancels pending branch B1 */ F14 CANCEL Proxy -> B1 CANCEL sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Max-Forwards: 70 From: BigGuy To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 CANCEL Content-Length: 0 F15 200 OK B1 -> Proxy Johnston, et al. Informational [Page 95] Internet Draft SIP Service Examples November 2002 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 From: BigGuy To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 CANCEL Content-Length: 0 F16 487 Request Terminated B1 -> Proxy SIP/2.0 487 Request Terminated Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F17 ACK Proxy -> B1 ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F18 ACK A -> Proxy ACK sip:UserB4@client3.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F19 ACK Proxy -> B3 ACK sip:UserB4@client3.there.com SIP/2.0 Johnston, et al. Informational [Page 96] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.3 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* RTP streams are established between A and B3*/ /* User B3 sends a NOTIFY to the group with established dialog information. */ F20 NOTIFY B3 -> Proxy NOTIFY sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk Max-Forwards: 70 From: LittleGuy ;tag=w2Hu8sj To: LittleGuy Call-ID: 8458999275@there.com CSeq: 1 NOTIFY Event: dialog Subscription-State: active;expires=3600 Content-Type: application/dialog-info+xml Content-Length: ... confirmed F21 NOTIFY Proxy -> B1 NOTIFY sip:UserB1@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.115 Max-Forwards: 69 From: LittleGuy ;tag=w2Hu8sj To: LittleGuy Call-ID: 8458999275@there.com CSeq: 1 NOTIFY Event: dialog Johnston, et al. Informational [Page 97] Internet Draft SIP Service Examples November 2002 Subscription-State: active;expires=3600 Content-Type: application/dialog-info+xml Content-Length: ... confirmed F22 Proxy -> B2 NOTIFY sip:UserB1@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.2 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.115 Max-Forwards: 69 From: LittleGuy ;tag=w2Hu8sj To: LittleGuy Call-ID: 8458999275@there.com CSeq: 1 NOTIFY Event: dialog Subscription-State: active;expires=3600 Content-Type: application/dialog-info+xml Content-Length: ... confirmed F23 NOTIFY Proxy-> B3 NOTIFY sip:UserB1@client3.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.3 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.115 Max-Forwards: 69 From: LittleGuy ;tag=w2Hu8sj To: LittleGuy Call-ID: 8458999275@there.com CSeq: 1 NOTIFY Event: dialog Johnston, et al. Informational [Page 98] Internet Draft SIP Service Examples November 2002 Subscription-State: active;expires=3600 Content-Type: application/dialog-info+xml Content-Length: ... confirmed F24 200 OK B1 -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.115 From: LittleGuy ;tag=w2Hu8sj To: LittleGuy Call-ID: 8458999275@there.com CSeq: 1 NOTIFY Content-Length: 0 F25 200 OK Proxy -> B3 SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.115 From: LittleGuy ;tag=w2Hu8sj To: LittleGuy Call-ID: 8458999275@there.com CSeq: 1 NOTIFY Content-Length: 0 F26 200 OK B2 -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.2 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.115 From: LittleGuy ;tag=w2Hu8sj To: LittleGuy Call-ID: 8458999275@there.com CSeq: 1 NOTIFY Content-Length: 0 Johnston, et al. Informational [Page 99] Internet Draft SIP Service Examples November 2002 F27 200 OK B3 -> Proxy SIP/2.0 482 Loop Detected Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.3 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.115 From: LittleGuy ;tag=w2Hu8sj To: LittleGuy Call-ID: 8458999275@there.com CSeq: 1 NOTIFY Content-Length: 0 /* User B2 decided to join the call. */ F28 INVITE B2 -> Proxy INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk Max-Forwards: 70 From: LittleGuy ;tag=4524524312 To: LittleGuy Call-ID: 524251233@there.com CSeq: 1 INVITE Contact: Join: 12345600@here.com;to-tag=765432;from-tag=1234567 Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client2.there.com s=Session SDP c=IN IP4 client2.there.com t=0 0 m=audio 3458 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F29 INVITE Proxy -> B1 INVITE sip:UserB1@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.114 Max-Forwards: 69 From: LittleGuy ;tag=4524524312 To: LittleGuy Call-ID: 524251233@there.com CSeq: 1 INVITE Johnston, et al. Informational [Page 100] Internet Draft SIP Service Examples November 2002 Contact: Join: 12345600@here.com;to-tag=765432;from-tag=1234567 Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client2.there.com s=Session SDP c=IN IP4 client2.there.com t=0 0 m=audio 3458 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F30 INVITE Proxy -> B2 INVITE sip:UserB1@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.2 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.114 Max-Forwards: 69 From: LittleGuy ;tag=4524524312 To: LittleGuy Call-ID: 524251233@there.com CSeq: 1 INVITE Contact: Join: 12345600@here.com;to-tag=765432;from-tag=1234567 Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client2.there.com s=Session SDP c=IN IP4 client2.there.com t=0 0 m=audio 3458 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F31 INVITE Proxy -> B1 INVITE sip:UserB1@client3.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.3 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.114 Max-Forwards: 69 From: LittleGuy ;tag=4524524312 To: LittleGuy Call-ID: 524251233@there.com CSeq: 1 INVITE Contact: Johnston, et al. Informational [Page 101] Internet Draft SIP Service Examples November 2002 Join: 12345600@here.com;to-tag=765432;from-tag=1234567 Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client2.there.com s=Session SDP c=IN IP4 client2.there.com t=0 0 m=audio 3458 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F32 100 Trying Proxy -> B2 SIP/2.0 100 Trying Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.114 From: LittleGuy ;tag=4524524312 To: LittleGuy Call-ID: 524251233@there.com CSeq: 1 INVITE Content-Length: 0 /* B1 does not have an established dialog, so it returns a 481 */ F33 481 Dialog Does Not Exist B1 -> Proxy SIP/2.0 481 Dialog Does Not Exist Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.3 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.114 From: LittleGuy ;tag=4524524312 To: LittleGuy ;tag=68324lk42jd Call-ID: 524251233@there.com CSeq: 1 INVITE Content-Length: 0 F34 ACK Proxy -> B1 ACK sip:UserB1@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.3 From: LittleGuy ;tag=4524524312 To: LittleGuy ;tag=68324lk42jd Call-ID: 524251233@there.com CSeq: 1 ACK Content-Length: 0 Johnston, et al. Informational [Page 102] Internet Draft SIP Service Examples November 2002 F35 482 Loop Detected B2 -> Proxy SIP/2.0 482 Loop Detected Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.2 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.114 From: LittleGuy ;tag=4524524312 To: LittleGuy ;tag=134lkwe Call-ID: 524251233@there.com CSeq: 1 INVITE Content-Length: 0 F36 ACK Proxy -> B2 ACK sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.2 From: LittleGuy ;tag=4524524312 To: LittleGuy ;tag=134lkwe Call-ID: 524251233@there.com CSeq: 1 ACK Content-Length: 0 /* B3 has an existing dialog and agrees to mix B2 into the session. */ F37 200 OK User B3 -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK4558a.3 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.114 From: LittleGuy ;tag=4524524312 To: LittleGuy ;tag=3891908734 Call-ID: 524251233@there.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client3.there.com s=Session SDP c=IN IP4 client3.there.com t=0 0 m=audio 3460 RTP/AVP 0 a=rtpmap:0 PCMU/8000 Johnston, et al. Informational [Page 103] Internet Draft SIP Service Examples November 2002 F38 200 OK User B3 -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk ;received=192.0.2.114 Max-Forwards: 69 From: LittleGuy ;tag=4524524312 To: LittleGuy ;tag=3891908734 Call-ID: 524251233@there.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client3.there.com s=Session SDP c=IN IP4 client3.there.com t=0 0 m=audio 3460 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F39 ACK B2 -> B3 ACK sip:UserB3@client3.there.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKq0qwli6ewlk Max-Forwards: 69 From: LittleGuy ;tag=4524524312 To: LittleGuy ;tag=3891908734 Call-ID: 524251233@there.com CSeq: 1 ACK Content-Length: 0 Johnston, et al. Informational [Page 104] Internet Draft SIP Service Examples November 2002 2.12 Find-Me User A Proxy User User User User B1 B2 B3 B4 | | | | | | | INVITE F1 | | | | | |--------------->| INVITE F2 | | | | | |------------->| | | | |(100 Trying) F3 | | | | | |<---------------|180 Ringing F4| | | | | |<-------------| | | | | 180 Ringing F5 | | | | | |<---------------| | | | | | | Timeout | | | | | | | | | | | | CANCEL F6 | | | | | |------------->| | | | | | 200 OK F7 | | | | | |<-------------| | | | | | 487 F8 | | | | | |<-------------| | | | | | ACK F9 | | | | | |------------->| | | | | | INVITE F10 | | | | |-------------------->| | | | |480 Not Logged In F11| | | | |<--------------------| | | | | ACK F12| | | | |-------------------->| | | | | INVITE F13 | | | |--------------------------->| | | | 486 Busy Here F14 | | | |<---------------------------| | | | ACK F15 | | | |--------------------------->| | | | INVITE F16 | | |---------------------------------->| | | 180 Ringing F17 | | 180 F18 |<----------------------------------| |<---------------| 200 OK F19 | | 200 OK F20 |<----------------------------------| |<---------------| | | ACK F21 | | |--------------->| ACK F22 | | |---------------------------------->| | Both way RTP Established | |<==================================================>| | | BYE F23 | | BYE F24 |<----------------------------------| |<---------------| | | 200 OK F25 | | Johnston, et al. Informational [Page 105] Internet Draft SIP Service Examples November 2002 |--------------->| 200 OK F26 | | |---------------------------------->| | | | A call to a user will attempt to locate that user by calling locations from a list of contacts. The location to answer the call becomes the active set, no other sets may join the call. While this flow shows a sequential search, the search could be accomplished using parallel forking, as in the previous example. Message Details F1 INVITE A -> Proxy INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t= 0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 INVITE Proxy -> B1 INVITE sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... Johnston, et al. Informational [Page 106] Internet Draft SIP Service Examples November 2002 v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t= 0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F3 (100 Trying) Proxy -> A SIP/2.0 100 Trying Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F4 180 Ringing B1 -> Proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F5 180 Ringing Proxy -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 /* B1 rings for until a configurable timer in the Proxy expires. The Johnston, et al. Informational [Page 107] Internet Draft SIP Service Examples November 2002 Proxy then sends Cancel and proceeds down the list of routes. */ F6 CANCEL Proxy -> B1 CANCEL sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Max-Forwards: 70 From: BigGuy To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 CANCEL Content-Length: 0 F7 200 OK B1 -> Proxy SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 From: BigGuy To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 CANCEL Content-Length: 0 F8 487 Request Terminated B1 -> Proxy SIP/2.0 487 Request Terminated Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F9 ACK Proxy -> B1 ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=765432 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 Johnston, et al. Informational [Page 108] Internet Draft SIP Service Examples November 2002 F10 INVITE Proxy -> B2 INVITE sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F11 480 Not Logged In B2 -> Proxy SIP/2.0 480 Not Logged In Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 ;received=192.0.2.54 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314756 Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F12 ACK Proxy -> B2 ACK sip:UserB2@client2.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.2 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314756 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F13 INVITE Proxy -> B3 Johnston, et al. Informational [Page 109] Internet Draft SIP Service Examples November 2002 INVITE sip:UserB3@client3.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.3 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F14 486 Busy Here B3 -> Proxy SIP/2.0 486 Busy Here Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.3 ;received=192.0.2.54 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F15 ACK Proxy -> B3 ACK sip:UserB3@client3.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.3 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7654321 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F16 INVITE Proxy -> B4 INVITE sip:UserB4@client4.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=83749.4 Johnston, et al. Informational [Page 110] Internet Draft SIP Service Examples November 2002 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F17 180 Ringing B4 -> Proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=83749.4 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F18 180 Ringing B4 -> Proxy SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F19 200 OK B4 -> Proxy Johnston, et al. Informational [Page 111] Internet Draft SIP Service Examples November 2002 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=83749.4 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client4.there.com s=Session SDP c=IN IP4 client4.there.com t=0 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F20 200 OK Proxy -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Record-Route: From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client4.there.com s=Session SDP c=IN IP4 client4.there.com t=0 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F21 ACK A -> Proxy ACK sip:UserB4@client4.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Route: Max-Forwards: 70 From: BigGuy ;tag=1234567 Johnston, et al. Informational [Page 112] Internet Draft SIP Service Examples November 2002 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F22 ACK Proxy -> B4 ACK sip:UserB4@client4.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 Max-Forwards: 69 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7137136 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* RTP streams are established between A and B4*/ /* User B4 Hangs Up with User A. */ F23 BYE B4 -> Proxy BYE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Route: Max-Forwards: 70 From: LittleGuy ;tag=7137136 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1 BYE Content-Length: 0 F24 BYE Proxy -> A BYE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 Max-Forwards: 69 From: LittleGuy ;tag=7137136 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1 BYE Content-Length: 0 F25 200 OK A -> Proxy Johnston, et al. Informational [Page 113] Internet Draft SIP Service Examples November 2002 SIP/2.0 200 OK Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 ;received=192.0.2.54 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: LittleGuy ;tag=7137136 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1 BYE Content-Length: 0 F26 200 OK Proxy -> B4 SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: LittleGuy ;tag=7137136 To: BigGuy ;tag=1234567 Call-ID: 12345600@here.com CSeq: 1 BYE Content-Length: 0 Johnston, et al. Informational [Page 114] Internet Draft SIP Service Examples November 2002 2.13 Call Management (Incoming Call Screening) User A Proxy User B | | | | INVITE F1 | | |------------------------------>| | 305 Use Proxy F2 | |<------------------------------| | ACK F3 | | |------------------------------>| | INVITE F4 | | |--------------->| | | 407 Proxy Authorization F5 | |<---------------| | | ACK F6 | | |--------------->| | | INVITE F7 | | |--------------->| | | 403 Screening Failure (Terminating) F8 |<---------------| | | ACK F9 | | |--------------->| | | | | User B has an incoming call screening list, User A is included on the list of addresses User B will not accept calls from. User A attempts to call user B. Messages F1, F2, and F3 are included to show that User B does not accept INVITEs that have not been screened by the proxy. Note that call screening can not be done using the From header û instead some form of authentication credentials must be used. Message Details F1 INVITE A -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 Johnston, et al. Informational [Page 115] Internet Draft SIP Service Examples November 2002 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 /* User B only accepts INVITEs that have been screened by the proxy */ F2 305 Use Proxy B -> A SIP/2.0 305 Use Proxy Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=342123 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F3 ACK A -> B ACK sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=342123 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* A retries the call through the proxy */ F4 INVITE A -> Proxy 1 INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 2 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 Johnston, et al. Informational [Page 116] Internet Draft SIP Service Examples November 2002 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 /* Proxy 1 challenges User A for authentication */ F5 407 Proxy Authorization Required Proxy 1 -> A SIP/2.0 407 Proxy Authorization Required Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7886765 Call-ID: 12345600@here.com CSeq: 2 INVITE Proxy-Authenticate: Digest realm="wcom.com", domain="sip:ss1.wcom.com", nonce="ea9c8e88df84f1cec4341ae6cbe5a359", opaque="", stale=FALSE, algorithm=MD5 Content-Length: 0 F6 ACK A -> Proxy 1 ACK sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=7886765 Call-ID: 12345600@here.com CSeq: 2 ACK Content-Length: 0 /* User A responds by sending an INVITE with authentication credentials in it. */ F7 INVITE A -> Proxy 1 INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 3 INVITE Contact: Proxy-Authorization: Digest username="UserA", realm="wcom.com", nonce="ae9137be1c87d175c2dd63302a0d6e0a", Johnston, et al. Informational [Page 117] Internet Draft SIP Service Examples November 2002 opaque="", uri="sip:UserB@there.com", response="bbaec39f943bdcb3620d90afc548a45c" Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F8 403 Screening Failure (Terminating) Proxy 1 -> A SIP/2.0 403 Screening Failure (Terminating) Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=ffe254 Call-ID: 12345600@here.com CSeq: 3 INVITE Error-Info: Content-Length: 0 F9 ACK A -> Proxy 1 ACK sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=ffe254 Call-ID: 12345600@here.com CSeq: 3 ACK Content-Length: 0 Johnston, et al. Informational [Page 118] Internet Draft SIP Service Examples November 2002 2.14 Call Management (Outgoing Call Screening) User A Proxy User B | | | | INVITE F1 | | |--------------->| | | 407 Proxy Authorization F2 | |<---------------| | | ACK F3 | | |--------------->| | | INVITE F4 | | |--------------->| | | 403 Screening Failure (Originating) F5 |<---------------| | | ACK F6 | | |--------------->| | | | | User A has an outgoing call screening list, User B is included on the list of addresses User A will not be able to place a call to. User A attempts to call user B. Message Details F1 INVITE A -> Proxy 1 INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 /* Proxy 1 challenges User A for authentication */ F2 407 Proxy Authorization Required Proxy 1 -> A Johnston, et al. Informational [Page 119] Internet Draft SIP Service Examples November 2002 SIP/2.0 407 Proxy Authorization Required Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=90210 Call-ID: 12345600@here.com CSeq: 1 INVITE Proxy-Authenticate: Digest realm="wcom.com", domain="sip:ss1.wcom.com", nonce="ea9c8e88df84f1cec4341ae6cbe5a359", opaque="", stale=FALSE, algorithm=MD5 Content-Length: 0 F3 ACK A -> Proxy 1 ACK sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=90210 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 /* User A responds be sending an INVITE with authentication credentials in it. */ F4 INVITE A -> Proxy 1 INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 2 INVITE Contact: Proxy-Authorization: Digest username="UserA", realm="wcom.com", nonce="cb360afc54bbaec39f943bd820d9a45c", opaque="", uri="sip:UserB@there.com", response="b9d2e5bcdec9f69ab2a9b44f270285a6" Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 Johnston, et al. Informational [Page 120] Internet Draft SIP Service Examples November 2002 F5 403 Screening Failure (Originating) Proxy 1 -> A SIP/2.0 403 Screening Failure (Originating) Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=18017 Call-ID: 12345600@here.com CSeq: 2 INVITE Error-Info: Content-Length: 0 F6 ACK A -> Proxy 1 ACK sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=18017 Call-ID: 12345600@here.com CSeq: 2 ACK Content-Length: 0 Johnston, et al. Informational [Page 121] Internet Draft SIP Service Examples November 2002 2.15 Call Park User A User B Park Server User C | | | | | INVITE F1 | | | |------------->| | | |180 Ringing F2| | | |<-------------| | | | 200 OK F3 | | | |<-------------| | | | ACK F4 | | | |------------->| | | | RTP Media | | | |<============>| | | | User B Parks Call | | | | REFER Refer-To: A F5 | | |------------->| | | | 202 F6 | | | |<-------------| | | | NOTIFY F7 | | | |<-------------| | | | 200 F8 | | | |------------->| | | INVITE F9 Replaces: B | | |<----------------------------| | | 200 OK F10 | | |---------------------------->| | | ACK F11 | | |<----------------------------| | | RTP Music | | |<===========================>| | | BYE F12 | | | |------------->| NOTIFY F14 | | | 200 OK F13 |<-------------| | |<-------------| 200 OK F15 | | | |------------->| | | | User C picks up the call | | | | | | INVITE Replaces: Park Server F16 | |<-------------------------------------------| | | | 200 F17 | |------------------------------------------->| | | | ACK F18 | |<-------------------------------------------| | RTP Media | |<==========================================>| | BYE F19 | | |---------------------------->| | | 200 OK F20 | | |<----------------------------| | | No more RTP Music | | Johnston, et al. Informational [Page 122] Internet Draft SIP Service Examples November 2002 In this example, User A calls User B. User B then parks the call at the Park Server by sending a REFER to the Park Server. The server sends an INVITE to A which replaces the session between A and B. The call is accepted by A and causes A to send a BYE to B. User B receives notification of the successful park, and also receives the Call-ID in the application/sip body of the NOTIFY response. User C wishes to retrieve the call, a new INVITE is sent to A which replaces the session with the Park Server. User A accepts the call and sends a BYE to the Park Server. Note that if the Park Server did not return the dialog identifiers (Call-ID, To and From tags) in the NOTIFY, C could send a SUBSCRIBE to retrieve this information. Note that this call is a special case of call transfer. Note also that this flow could also be used for Music on Hold. Message Details. F1 INVITE A -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 180 Ringing B -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com Johnston, et al. Informational [Page 123] Internet Draft SIP Service Examples November 2002 CSeq: 1 INVITE Contact: Content-Length: 0 F3 200 OK B -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F4 ACK A -> B ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 1 ACK Content-Length: 0 /* User B REFERs Park Server to establish session with A which replaces the established session between A and B. Note that there is no session established between B and the Park Server. */ F5 REFER B -> Park Server REFER sip:park@server.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: LittleGuy ;tag=02134 To: Park Server Call-ID: 4802029847@there.com CSeq: 1 REFER Johnston, et al. Informational [Page 124] Internet Draft SIP Service Examples November 2002 Refer-To: Referred-By: Contact: Content-Length: 0 F6 202 Accepted Park Server -> B SIP/2.0 202 Accepted Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: LittleGuy ;tag=02134 To: Park Server ;tag=56323 Call-ID: 4802029847@there.com CSeq: 1 REFER Content-Length: 0 F7 NOTIFY Park Server -> B NOTIFY sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 To: LittleGuy ;tag=02134 Max-Forwards: 70 From: Park Server ;tag=56323 Call-ID: 4802029847@there.com CSeq: 1 NOTIFY Event: refer Subscription-State: active;expires=60 Content-Type: message/sipfrag Content-Length: ... SIP/2.0 100 Trying F8 200 OK B -> Park Server SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 To: LittleGuy ;tag=02134 From: Park Server ;tag=56323 Call-ID: 4802029847@there.com CSeq: 1 NOTIFY Content-Length: 0 /* Park Server places call to User A to replace session between A and B */ F9 INVITE Park Server -> A Johnston, et al. Informational [Page 125] Internet Draft SIP Service Examples November 2002 INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP server.com:5060 Max-Forwards: 70 From: ;tag=0111 To: Call-ID: a5-75-34-12-76@server.com CSeq: 1 INVITE Referred-By: Contact: Replaces: 12345601@here.com;from-tag=314159;to-tag=1234567 Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Content-Type: application/sdp Content-Length: ... v=0 o=ParkServer 2890844576 2890844576 IN IP4 Park.server.com s=Session SDP c=IN IP4 music.server.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F10 200 OK A-> Park Server SIP/2.0 200 OK Via: SIP/2.0/UDP music.server.com:5060 From: ;tag=0111 To: BigGuy ;tag=098594 Call-ID: a5-75-34-12-76@server.com CSeq: 1 INVITE Contact: Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=recvonly F11 ACK Park Server -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP music.server.com:5060 Max-Forwards: 70 Johnston, et al. Informational [Page 126] Internet Draft SIP Service Examples November 2002 From: ;tag=0111 To: BigGuy ;tag=098594 Call-ID: a5-75-34-12-76@server.com CSeq: 1 ACK Content-Length: 0 F12 BYE A -> B ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 2 BYE Content-Length: 0 F13 200 OK B -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.there.com:5060;branch=z9hG4bKnashds7 ;received=192.0.2.105 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=314159 Call-ID: 12345601@here.com CSeq: 2 BYE Content-Length: 0 /* Park Server reports success back to B by returning all the SIP headers in 200 OK response */ F14 NOTIFY Park Server -> B NOTIFY sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 To: LittleGuy ;tag=02134 Max-Forwards: 70 From: Park Server ;tag=56323 Call-ID: 4802029847@there.com CSeq: 1 NOTIFY Event: refer Subscription-State: terminated;reason=noresource Content-Type: message/sipfrag Content-Length: ... SIP/2.0 200 OK Via: SIP/2.0/UDP music.server.com:5060 From: ;tag=0111 To: BigGuy ;tag=098594 Johnston, et al. Informational [Page 127] Internet Draft SIP Service Examples November 2002 Call-ID: a5-75-34-12-76@server.com CSeq: 2 INVITE Contact: F15 200 OK B -> Park Server SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 To: LittleGuy ;tag=02134 From: Park Server ;tag=56323 Call-ID: 4802029847@there.com CSeq: 2 NOTIFY Content-Length: 0 /* User A is now parked at the Park Server */ /* User C picks up the call by sending an INVITE to A which replaces the existing session with the Park/Park Server. C needs to know the dialog information to construct the Replaces header. */ F16 INVITE C -> A INVITE sip:UserA@here.com SIP/2.0 Via: SIP/2.0/UDP client.anywhere.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: OtherGuy ;tag=5893461 To: BigGuy Call-ID: 6485356@anywhere.com CSeq: 1 INVITE Contact: Replaces: a5-75-34-12-76@server.com;from-tag=098594;to-tag=0111 Content-Type: application/sdp Content-Length: ... v=0 o=UserC 2890844922 2890844922 IN IP4 client.anywhere.com s=Session SDP c=IN IP4 client.anywhere.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F17 200 OK A -> C SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.105 Johnston, et al. Informational [Page 128] Internet Draft SIP Service Examples November 2002 From: OtherGuy ;tag=5893461 To: BigGuy ;tag=222 Call-ID: 6485356@anywhere.com CSeq: 1 INVITE Contact: Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844527 2890844527 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F18 ACK C -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: OtherGuy ;tag=5893461 To: BigGuy ;tag=222 Call-ID: 6485356@anywhere.com CSeq: 1 ACK Content-Length: 0 /* A replaces the session to the Park Server with the new session with C and generates a BYE to disconnect the Park Server */ F19 BYE A -> Park Server BYE sip:park@server.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=098594 To: ;tag=0111 Call-ID: a5-75-34-12-76@server.com CSeq: 1 BYE Content-Length: 0 F20 200 OK Park Server -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=098594 To: ;tag=0111 Johnston, et al. Informational [Page 129] Internet Draft SIP Service Examples November 2002 Call-ID: a5-75-34-12-76@server.com CSeq: 1 BYE Content-Length: 0 Johnston, et al. Informational [Page 130] Internet Draft SIP Service Examples November 2002 2.16 Call Pickup User A User B User D | | | | INVITE F1 | | |------------->| | |180 Ringing F2| | |<-------------| | | | SUBSCRIBE F3 | | |<------------------| | | 200 OK F4 | | |------------------>| | | NOTIFY F5 | | |------------------>| | | 200 OK F6 | | |<------------------| | INVITE Replaces:B F7 | |<---------------------------------| | | 200 OK F8 | |--------------------------------->| | CANCEL F9 | | |------------->| | | 200 OK F10 | | |<-------------| | | 487 F11 | | |<-------------| | | ACK F12 | | |------------->| | | ACK F13 | |<---------------------------------| | | NOTIFY F14 | | |------------------>| | | 481 F15 | | |<------------------| | | | Both way RTP Established | |<================================>| | BYE F16 | |--------------------------------->| | 200 OK F17 | |<---------------------------------| | | User B and D are part of a work group at client.there.com that can pick up each others calls. User A calls B who does not answer. User D wishes to pick up the call and sends a SUBSCRIBE to B to retrieve the dialog information. D then generates an INVITE with a Replaces to A. A answers the INVITE and sends a CANCEL to stop BÆs phone ringing. Note that the order of the CANCEL/ACK sequence in F11 through F20 is not significant. Johnston, et al. Informational [Page 131] Internet Draft SIP Service Examples November 2002 Message Details F1 INVITE A -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=0 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 180 Ringing B1 -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=3145678 Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Length: 0 /* User B decides to pick up the call */ F3 SUBSCRIBE D -> B SUBSCRIBE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP smallguy.there.com:5060;branch=z9hG4bK74bf Max-Forwards: 70 From: SmallGuy ;tag=8675309 To: LittleGuy Call-ID: rt4353gs2egg@smallguy.there.com CSeq: 1 INVITE Johnston, et al. Informational [Page 132] Internet Draft SIP Service Examples November 2002 Contact: Event: dialog Subscription-State: active;expires=3600 Accept: application/dialog-info+xml Content-Length: 0 F4 200 OK B -> D SIP/2.0 200 OK Via: SIP/2.0/UDP smallguy.there.com:5060;branch=z9hG4bK74bf ;received=192.0.2.114 Max-Forwards: 70 From: SmallGuy ;tag=8675309 To: LittleGuy ;tag=31451098 Call-ID: rt4353gs2egg@smallguy.there.com CSeq: 1 INVITE Content-Length: 0 F5 NOTIFY B -> D NOTIFY sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP littleguy.there.com:5060;branch=z9hG4bK74bf Max-Forwards: 70 From: LittleGuy ;tag=31451098 To: SmallGuy ;tag=8675309 Call-ID: rt4353gs2egg@smallguy.there.com CSeq: 1 NOTIFY Contact: Event: dialog Subscription-State: active;expires=3600 Content-Type: application/dialog-info+xml Content-Length: ... early F6 200 OK D -> B SIP/2.0 200 OK Via: SIP/2.0/UDP littleguy.there.com:5060;branch=z9hG4bK74bf From: LittleGuy ;tag=31451098 To: SmallGuy ;tag=8675309 Call-ID: rt4353gs2egg@smallguy.there.com Johnston, et al. Informational [Page 133] Internet Draft SIP Service Examples November 2002 CSeq: 1 NOTIFY Contact: Content-Length: 0 F7 INVITE D -> A INVITE sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP smallguy.there.com:5060;branch=z9hG4bK74bf Max-Forwards: 70 From: SmallGuy ;tag=8675309 To: BigGuy Call-ID: 563456212@b2.there.com CSeq: 1 INVITE Replaces: 12345600@here.com;to-tag=314578;from-tag=1234567 Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890843122 2890843122 IN IP4 smallguy.there.com s=Session SDP c=IN IP4 client2.there.com t=3034423619 0 m=audio 5342 RTP/AVP 0 a=rtpmap:0 PCMU/8000 /* A matches the dialog information in the Replaces header and accepts the INVITE */ F8 200 OK A -> D SIP/2.0 200 OK Via: SIP/2.0/UDP smallguy.there.com:5060;branch=z9hG4bK74bf ;received=192.0.2.114 From: SmallGuy ;tag=8675309 To: BigGuy ;tag=131256 Call-ID: 563456212@b2.there.com CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY Supported: replaces Content-Type: application/sdp Content-Length: ... v=0 o=UserA 289084543 289084543 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com Johnston, et al. Informational [Page 134] Internet Draft SIP Service Examples November 2002 t=0 0 m=audio 49172 RTP/AVP 0 a=rtpmap:0 PCMU/8000 /* A stops BÆs phone from ringing by sending a CANCEL */ F9 CANCEL A -> B CANCEL sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 CANCEL Content-Length: 0 F10 200 OK B -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 CANCEL Content-Length: 0 F11 487 Request Terminated B1 -> Proxy SIP/2.0 487 Request Terminated Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=3145678 Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F12 ACK A -> B ACK sip:UserB1@client.there.com SIP/2.0 Via: SIP/2.0/UDP ss1.wcom.com:5060;branch=z9hG4bK83749.1 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=3145678 Call-ID: 12345600@here.com Johnston, et al. Informational [Page 135] Internet Draft SIP Service Examples November 2002 CSeq: 1 ACK Content-Length: 0 Content-Length: 0 F13 ACK D -> A ACK sip:UserA@client.here.com SIP/2.0 Via: SIP/2.0/UDP b2.there.com:5060;branch=z9hG4bK74bf Max-Forwards: 70 From: LittleGuy ;tag=8675309 To: BigGuy ;tag=131256 Call-ID: 563456212@b2.there.com CSeq: 1 ACK Content-Length: 0 F14 NOTIFY B -> D NOTIFY sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP littleguy.there.com:5060;branch=z9hG4bK74bf Max-Forwards: 70 From: LittleGuy ;tag=31451098 To: SmallGuy ;tag=8675309 Call-ID: rt4353gs2egg@smallguy.there.com CSeq: 2 NOTIFY Contact: Event: dialog Subscription-State: active;expires=3600 Content-Type: application/dialog-info+xml Content-Length: ... terminated F15 481 Dialog Does Not Exist D -> B SIP/2.0 481 Dialog Does Not Exist Via: SIP/2.0/UDP littleguy.there.com:5060;branch=z9hG4bK74bf From: LittleGuy ;tag=31451098 To: SmallGuy ;tag=8675309 Call-ID: rt4353gs2egg@smallguy.there.com CSeq: 2 NOTIFY Contact: Johnston, et al. Informational [Page 136] Internet Draft SIP Service Examples November 2002 Content-Length: 0 /* RTP streams are established between A and D. User A Hangs Up with User B. */ F16 BYE A -> Proxy BYE sip:UserD@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 To: LittleGuy ;tag=8675309 From: BigGuy ;tag=131256 Call-ID: 563456212@b2.there.com CSeq: 2 BYE Content-Length: 0 F17 200 OK D -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 To: LittleGuy ;tag=8675309 From: BigGuy ;tag=131256 Call-ID: 563456212@b2.there.com CSeq: 2 BYE Content-Length: 0 Johnston, et al. Informational [Page 137] Internet Draft SIP Service Examples November 2002 2.17 Automatic Redial User A User B | | | INVITE F1 | |--------------->| |486 Busy Here F2| |<---------------| User B is busy | ACK F3 | |--------------->| | SUBSCRIBE F4 | |--------------->| | 200 OK F5 | |<---------------| | NOTIFY F6 | |<---------------| | 200 OK F7 | |--------------->| | | | NOTIFY F8 | User B is now available |<---------------| | 200 OK F9 | |--------------->| | | | INVITE F10 | |--------------->| Session setup successfully | 180 Ringing F11| |<---------------| | 200 OK F12 | |<---------------| | ACK F13 | |--------------->| | Media Session | |<==============>| | | User B is initially busy when User A calls. User A subscribes to User BÆs call state using a SUBSCRIBE F4. User B sends a NOTIFY F8 when User B is available. A is alerted, then User A sends an INVITE to B to establish the session. Message Details F1 INVITE A -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 Johnston, et al. Informational [Page 138] Internet Draft SIP Service Examples November 2002 To: LittleGuy Call-ID: 12345600@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F2 486 Busy Here SIP/2.0 486 Busy Here Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=982039i4 Call-ID: 12345600@here.com CSeq: 1 INVITE Content-Length: 0 F3 ACK A -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=1234567 To: LittleGuy ;tag=982039i4 Call-ID: 12345600@here.com CSeq: 1 ACK Content-Length: 0 F4 SUBSCRIBE A -> B SUBSCRIBE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=837348234 To: LittleGuy Call-ID: 4524526232@here.com CSeq: 1 SUBSCRIBE Contact: UserA@client.here.com Event: dialog Subscription-State: active;expires=3600 Accept: application/dialog-info+xml Johnston, et al. Informational [Page 139] Internet Draft SIP Service Examples November 2002 Content-Length: 0 F5 200 OK B -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 From: BigGuy ;tag=837348234 To: LittleGuy Call-ID: 4524526232@here.com CSeq: 1 SUBSCRIBE Contact: UserB@client.there.com Content-Length: 0 F6 NOTIFY B -> A NOTIFY sip:UserA@here.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: LittleGuy ;tag=341123 To: BigGuy ;tag=837348234 Call-ID: 4524526232@here.com CSeq: 1 NOTIFY Event: dialog Subscription-State: active;expires=3600 Content-Type: application/dialog-info+xml Content-Length: ... confirmed F7 200 OK A -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 From: LittleGuy ;tag=341123 To: BigGuy ;tag=837348234 Call-ID: 4524526232@here.com CSeq: 1 NOTIFY Content-Length: 0 /* User B is now available */ F8 NOTIFY B -> A Johnston, et al. Informational [Page 140] Internet Draft SIP Service Examples November 2002 NOTIFY sip:UserA@here.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: LittleGuy ;tag=341123 To: BigGuy ;tag=837348234 Call-ID: 4524526232@here.com CSeq: 2 NOTIFY Event: dialog Subscription-State: active;expires=3600 Content-Type: application/dialog-info+xml Content-Length: ... terminated F9 200 OK A -> B SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 From: LittleGuy ;tag=341123 To: BigGuy ;tag=837348234 Call-ID: 4524526232@here.com CSeq: 2 NOTIFY Content-Length: 0 Message Details F10 INVITE A -> B INVITE sip:UserB@there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=f23fkg14k To: LittleGuy Call-ID: aoij4i9okitr@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserA 2890844526 2890844526 IN IP4 client.here.com s=Session SDP Johnston, et al. Informational [Page 141] Internet Draft SIP Service Examples November 2002 c=IN IP4 client.here.com t=3034423619 0 m=audio 49170 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F11 180 Ringing B -> A SIP/2.0 180 Ringing Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=f23fkg14k To: LittleGuy ;tag=23431 Call-ID: aoij4i9okitr@here.com CSeq: 1 INVITE Contact: Content-Length: 0 F12 200 OK B -> A SIP/2.0 200 OK Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 ;received=192.0.2.103 From: BigGuy ;tag=f23fkg14k To: LittleGuy ;tag=23431 Call-ID: aoij4i9okitr@here.com CSeq: 1 INVITE Contact: Content-Type: application/sdp Content-Length: ... v=0 o=UserB 2890844527 2890844527 IN IP4 client.there.com s=Session SDP c=IN IP4 client.there.com t=3034423619 0 m=audio 3456 RTP/AVP 0 a=rtpmap:0 PCMU/8000 F13 ACK A -> B ACK sip:UserB@client.there.com SIP/2.0 Via: SIP/2.0/UDP client.here.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: BigGuy ;tag=f23fkg14k To: LittleGuy ;tag=23431 Call-ID: aoij4i9okitr@here.com CSeq: 1 ACK Content-Length: 0 Johnston, et al. Informational [Page 142] Internet Draft SIP Service Examples November 2002 Johnston, et al. Informational [Page 143] Internet Draft SIP Service Examples November 2002 3 Security Considerations Since many of the examples in this document involve SIP call control, either peer-to-peer or 3pcc, the security considerations in the Multiparty Framework document [12] apply. Johnston, et al. Informational [Page 144] Internet Draft SIP Service Examples November 2002 4 IANA Considerations None. Johnston, et al. Informational [Page 145] Internet Draft SIP Service Examples November 2002 5 Acknowledgements The Automatic Call Back call flow is based on a call flow by Adam Roach. The Single Line Extension call flow is based on a call flow by Jonathan Rosenberg. The authors wish to thank the following individuals for their assistance and review of this call flows document: Rohan Mahey, Jonathan Rosenberg, Hemant Agrawal, Henry Sinnreich, Dean Willis, David Devanatham, Joe Pizzimenti, Matt Cannon, John Hearty, the whole MCI WorldCom IPOP Design team, Scott Orton, Greg Osterhout, Pat Sollee, Doug Weisenberg, Danny Mistry, Steve McKinnon, and Denise Ingram, Denise Caballero, Tom Redman, Ilya Slain, Pat Sollee, John Truetken, and others from MCI WorldCom, 3Com, Cisco, Lucent and Nortel. Johnston, et al. Informational [Page 146] Internet Draft SIP Service Examples November 2002 6 References [1] S. Bradner, "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996. [2] J. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002. [3] A. Johnston, S. Donovan, R. Sparks, C. Cunningham, D. Willis, J. Rosenberg, and H. Schulzrinne, "SIP Call Flow Examples", Internet Draft, Internet Engineering Task Force, February 2002, Work in Progress. [4] R. Sparks, "The Refer Method", Internet Draft, Internet Engineering Task Force, July 2002, Work in Progress. [5] B. Biggs, R. Dean, and R. Mahy, "The SIP Replaces header," Internet Draft, Internet Engineering Task Force, January 2002, Work in Progress. [6] R. Mahy and D. Petrie,"The SIP Join Header," Internet Engineering Task Force, October 2002, Work in Progress. [7] J. Rosenberg, J. Peterson, H. Schulzrinne, and G. Camarillo, "Third Party Call Control in SIP," Internet Engineering Task Force, March 2001, Work in Progress. [8] J. Rosenberg and H. Schulzrinne, "An Offer/Answer Model with SDP," RFC 3264, June 2002. [9] R. Sparks and A. Johnston, "SIP Call Control û Transfer," Internet Engineering Task Force, October 2002, Work in progress. [10] J. Rosenberg and H. Schulzrinne, "A Session Initiation Protocol (SIP) Event Package for Dialog State," Internet Engineering Task Force, June 2002, Work in progress. [11] A. Roach, "SIP-Specific Event Notification," RFC 3265, June 2002. [12] R. Mahy, B. Campbell, A. Johnston, D. Petrie, J. Rosenberg, and R. Sparks, "A Multi-party Application Framework for SIP," Internet Engineering Task Force, February 2002, Work in progress. Johnston, et al. Informational [Page 147] Internet Draft SIP Service Examples November 2002 7 Author's Addresses Alan Johnston Email: alan.johnston@wcom.com sip:alan.johnston@siptest.wcom.com Robert Sparks Email: rsparks@dynamicsoft.com Chris Cunningham Email: ccunningham@dynamicsoft.com Steve Donovan Email: sdonovan@dynamicsoft.com Kevin Summers Email: kevin.summers@sonusnet.com Copyright Notice "Copyright (C) The Internet Society 2002. All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Johnston, et al. Informational [Page 148]