Internet Engineering Task Force Roy Spitzer(Editor) INTERNET DRAFT Telogy Zacharias Bilalis (Editor) Category: Standards Track (?) Siemens Expires: August 1, 2000 Contributions from: Gunnar Hellstrom Omnitor James Rafferty Brooktrout Technology Glenn Parsons Nortel Networks Fax, Modem, Text Telephone Determination using Megaco/H.248 STATUS OF THIS MEMO This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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 document discusses the dynamic determination of Voice/Modem/FAX/Text Telephone over a single port using Megaco and refers to the packages described for Megaco. The document aims to become an Appendix to Megaco and to be the base for the "application guide". TABLE OF CONTENTS Spitzer, Bilalis [Page 1] Internet draft F, M, T Determination February 1, 2000 1. Introduction .. .. .. .. .. .. .. .. .. .. .. .. .. .. 2 2. Relay Ports supporting V.8 .. .. .. .. .. .. .. .. .. .. 2 3. Relay Ports for V.21 .. .. .. .. .. .. .. .. .. .. .. .. 10 4. References .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 10 1. Introduction This document discusses the dynamic determination of Voice/Modem/FAX/Text Telephone over a single port using Megaco and refers to the packages described for Megaco. The document aims to become an Appendix to Megaco and to be the base for the "application guide". 2 Relay Ports supporting V.8 Spitzer, Bilalis [Page 2] Internet draft F, M, T Determination February 1, 2000 Termination T1 MGC Termination T2 |<-ctx=NULL,MODify(T1)-------| | |--Resp--------------------->| | |<-Audit(capabilities)-------| | |--Resp(codecs)------------->| | off- | | | hook |--Notify(offhook)---------->| | |<-Resp----------------------| | Accumulate | | Digits|--Notify(number)----------->| | | |--Audit(capabilities)------>| |<-Resp----------------------| | | |<--Resp(codecs)-------------| |<-ADD CTX(T1,selectCODEC)---| | | |--ADD CTX(T2,select CODEC)->| |--Resp--------------------->| | | |<--Resp---------------------| | |--MOD CTX(T2,Sig=ring)----->| |<-MOD CTX(T1,Sig=ringback)--| |RING Ringback |<-Resp----------------------| Tone |--Resp--------------------->| |off- | |<-Notify(offhook)-----------|hook |<-MOD CTX(T1,Mode=sendrecv)-| | | |--Resp--------------------->| |--Resp--------------------->| | +------------------------------------------------------------------+ | Voice may be transferred between T1 and T2 | +------------------------------------------------------------------+ CNG | | | |--Notify(dtone=CNG)-------->| | | |--MOD CTX(T2,Sig=CNG)------>| |<-Resp----------------------| |CNG | |<-Resp----------------------| | | |CED | |<-Notify(dtone=CED)---------| |<-MOD CTX(T1,Sig=CED)-------| | CED | |--Resp--------------------->| |--Resp--------------------->| | | |-MOD CTX(T2,selectFAXCODEC)>| | | |load | |<-Resp----------------------|CODEC || | | | |V.21 | |<-Notify(dtone=V21flag)-----|flags Spitzer, Bilalis [Page 3] Internet draft F, M, T Determination February 1, 2000 |<-MOD CTX(T1,Sig=V21flag)---| | | |--Resp--------------------->| |--Resp--------------------->| | | | |V.21 | | |flags +------------------------------------------------------------------+ | Start FAX Communications | +------------------------------------------------------------------+ Voice to FAX Call with modem or Text Telephone Call possible (Termination on Media Gateway) - Switchover based on CED/ANS detection Figure 1. Switch to FAX based on CNG and CED If CNG and CED are detected, the MGC should switch to the FAX codec. If the CNG is not used for switching, a flow similar to Figure 2 can be used. Spitzer, Bilalis [Page 4] Internet draft F, M, T Determination February 1, 2000 Termination T1 MGC Termination T2 |<-ctx=NULL,MODify(T1)-------| | |--Resp--------------------->| | |<-Audit(capabilities)-------| | |--Resp(codecs)------------->| | off- | | | hook |--Notify(offhook)---------->| | |<-Resp----------------------| | Accumulate | | Digits|--Notify(number)----------->| | | |--Audit(capabilities)------>| |<-Resp----------------------| | | |<--Resp(codecs)-------------| |<-ADD CTX(T1,selectCODEC)---| | | |--ADD CTX(T2,select CODEC)->| |--Resp--------------------->| | | |<--Resp---------------------| | |--MOD CTX(T2,Sig=ring)----->| |<-MOD CTX(T1,Sig=ringback)--| |RING Ringback |<-Resp----------------------| Tone |--Resp--------------------->| |off- | |<-Notify(offhook)-----------|hook |<-MOD CTX(T1,Mode=sendrecv)-| | | |--Resp--------------------->| |--Resp--------------------->| | +------------------------------------------------------------------+ | Voice may be transferred between T1 and T2 | +------------------------------------------------------------------+ CNG not seen or not sent | | | | | | | | | | | | | |CED/ | |<-Notify(dtone=CED/ANS)-----|ANS |<-MOD CTX(T1,Sig=CED/ANS)---| | CED | |--Resp--------------------->| |--Resp--------------------->| | | |-MOD CTX(T2,selTextTelCODEC>| | | |load | |<-Resp----------------------|CODEC || | | | |V.21 | |<-Notify(dtone=V21flag)-----|flags |<-MOD CTX(T1,Sig=V21flag)---| | Spitzer, Bilalis [Page 5] Internet draft F, M, T Determination February 1, 2000 | |--Resp--------------------->| |--Resp--------------------->| | | |-MOD CTX(T2,selectFAXCODEC)>| |<-MOD CTX(T1,selFAXCODEC)---| |load | |<-Resp----------------------|CODEC load | | | CODEC|--Resp--------------------->| | | | |V.21 | |<-Notify(dtone=V21flag)-----|flags |<-MOD CTX(T1,Sig=V21flag)---| | | |--Resp--------------------->| |--Resp--------------------->| | +------------------------------------------------------------------+ | Start FAX Communications | +------------------------------------------------------------------+ Voice to FAX Call with modem or Text Telephone Call possible (Termination on Media Gateway) - Switchover based on CED/ANS detection, FAX switchover based on V.21 flag detection Figure 2. Switch to FAX based on V.21 Flags A CI tone may be sent prior to the CED/ANS tone. Spitzer, Bilalis [Page 6] Internet draft F, M, T Determination February 1, 2000 Termination T1 MGC Termination T2 |<-ctx=NULL,MODify(T1)-------| | |--Resp--------------------->| | |<-Audit(capabilities)-------| | |--Resp(codecs)------------->| | off- | | | hook |--Notify(offhook)---------->| | |<-Resp----------------------| | Accumulate | | Digits|--Notify(number)----------->| | | |--Audit(capabilities)------>| |<-Resp----------------------| | | |<--Resp(codecs)-------------| |<-ADD CTX(T1,selectCODEC)---| | | |--ADD CTX(T2,select CODEC)->| |--Resp--------------------->| | | |<--Resp---------------------| | |--MOD CTX(T2,Sig=ring)----->| |<-MOD CTX(T1,Sig=ringback)--| |RING Ringback |<-Resp----------------------| Tone |--Resp------------------->--| |off- | |<-Notify(offhook)-----------|hook |<-MOD CTX(T1,Mode=sendrecv)-| | | |--Resp--------------------->| |--Resp--------------------->| | +------------------------------------------------------------------+ | Voice may be transferred between T1 and T2 | +------------------------------------------------------------------+ CI | | | |-Notify(MdmToneEvent=CI)--->| | | |--MOD CTX(T2, Sig=CI)------>| |<-Resp----------------------| | CI | |<-Resp----------------------| | | |CED/ | |<-Notify(dtone=ANS)---------|ANS |<-MOD CTX(T1,Sig=ANS)------>| ANS | |--Resp--------------------->| |--Resp--------------------->| | | |-MOD CTX(T1,selTextTelCODEC>| | | |load | |<-Resp----------------------|CODEC || | | | |CM | |<-Notify(MdmToneEvent=CM)---| Spitzer, Bilalis [Page 7] Internet draft F, M, T Determination February 1, 2000 |<-MOD CTX(T1,Sig=CM)--------| | CM | |--Resp--------------------->| |--Resp--------------------->| | | |-MOD CTX(T2,selModemCODEC)->| |<-MOD CTX(T1,selModemCODEC)-| |load | |<-Resp----------------------|CODEC load | | | CODEC|--Resp--------------------->| | | | |CM | |<-Notify(MdmToneEvent=CM)---| |<-MOD CTX(T1,Sig=CM)--------| | CM | |--Resp--------------------->| |--Resp--------------------->| | +------------------------------------------------------------------+ | Start Modem Communications | +------------------------------------------------------------------+ Voice to Modem Call with FAX or Text Telephone Call possible (Termination on Media Gateway) - Switchover based on CED/ANS detection Figure 3. Modem Determination Based on ANS and CM Spitzer, Bilalis [Page 8] Internet draft F, M, T Determination February 1, 2000 Termination T1 MGC Termination T2 |<-ctx=NULL,MODify(T1)-------| | |--Resp--------------------->| | |<-Audit(capabilities)-------| | |--Resp(codecs)------------->| | off- | | | hook |--Notify(offhook)---------->| | |<-Resp----------------------| | Accumulate | | Digits|--Notify(number)----------->| | | |--Audit(capabilities)------>| |<-Resp----------------------| | | |<--Resp(codecs)-------------| |<-ADD CTX(T1,selectCODEC)---| | | |--ADD CTX(T2,select CODEC)->| |--Resp--------------------->| | | |<--Resp---------------------| | |--MOD CTX(T2,Sig=ring)----->| |<-MOD CTX(T1,Sig=ringback)--| |RING Ringback |<-Resp----------------------| Tone |--Resp------------------->--| |off- | |<-Notify(offhook)-----------|hook |<-MOD CTX(T1,Mode=sendrecv)-| | | |--Resp--------------------->| |--Resp--------------------->| | +------------------------------------------------------------------+ | Voice may be transferred between T1 and T2 | +------------------------------------------------------------------+ CI | | | |-Notify(TextPhoneSig=CIV18)>| | | |--MOD CTX(T2, Sig=CIV18)--->| |<-Resp----------------------| | CI | |<-Resp----------------------| | | |ANS | |<-Notify(dtone=ANS)---------| |<-MOD CTX(T1,Sig=ANS)------>| ANS | |--Resp--------------------->| |--Resp--------------------->| | | |-MOD CTX(T2,selTextTelCODEC>| | | |load | |<-Resp----------------------|CODEC || | | | | TXP | | | Spitzer, Bilalis [Page 9] Internet draft F, M, T Determination February 1, 2000 |--Notify(TextPhoneSig=TXP)->| | | |-MOD CTX(T2,Sig=TXP)------->| | |<-Resp----------------------| |<-Resp----------------------| | +------------------------------------------------------------------+ | Start Text Telephone Communications | +------------------------------------------------------------------+ Voice to Text Telephone Call with FAX or Modem Call possible (Termination on Media Gateway) - Switchover based on CED/ANS detection Figure 4. Text Telephone Determination 3 Relay Ports for V.21 TBD 4 References [1] ITU-T Recommendation T.30 (7/96) Procedures for document facsimile transmission in the general switched telephone network. [2] ITU-T Recommendation V.8 Procedures for starting sessions of data transmission over the public switched telephone network [3] ITU-T Recommendation V.8 bis Procedures for the identification and selection of common modes of operation between data circuit- termination equipment (DCEs). [4] ITU-T Recommendation V.18 Operational and interworking requirements for DCES operating in the text telephone mode. [5] ITU-T Recommendation V.25 Automatic answering equipment and/or parallel automatic calling equipment on the general switched tele- phone network. [6] ITU-T Recommendation V.21 (11/88) - 300 bits per second duplex modem standardized for use in the general switched telephone net- work tbl *.txt | nroff -ms | col -bx | f.pl > out Spitzer, Bilalis [Page 10]