Network Working Group E. Tacsik Internet-Draft Nokia Expires: August 26, 2004 February 26, 2004 DHCP option for IPv6 SIP Proxy address draft-tacsik-dhc-dhcp-ipv6-sip-proxy-00.txt 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. This Internet-Draft will expire on August 26, 2004. Copyright Notice Copyright (C) The Internet Society (2004). All Rights Reserved. Abstract This document defines a new Dynamic Host Configuration Protocol (DHCP-for-IPv4)site-specific (i.e. "Private Use") option that contains a list of IPv6 addresses for SIP proxy server(s) [RFC 2939]. This list of IPv6 SIP Proxy Server(s) may be used by a 3GPP2 mobile to locate an IPv6 SIP Proxy Server(s), and which may additionally indicate the version of IP the IMS supports. Tacsik Expires August 26, 2004 [Page 1] Internet-Draft DHCP option for IPv6 SIP Proxy address February 2004 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. 3GPP2 IPv6 SIP Server Address Option . . . . . . . . . . . . . 4 3. Security Considerations . . . . . . . . . . . . . . . . . . . 6 4. Intellectual Property Right Notice . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 8 References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 A. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9 Intellectual Property and Copyright Statements . . . . . . . . 10 Tacsik Expires August 26, 2004 [Page 2] Internet-Draft DHCP option for IPv6 SIP Proxy address February 2004 1. Introduction The Session Initiation Protocol (SIP) [RFC 2543] is an application-layer control protocol that can establish, modify and terminate multimedia sessions or calls. A SIP system has a number of logical components: user agents, proxy servers, redirect servers and registrars. User agents MAY contain SIP clients, proxy servers always do. This document specifies a new "Private Use", site-specific DHCP option [RFC 2939] that allows a 3GPP2 mobile SIP client to locate a local IPv6 SIP server that is to be used for all outbound SIP requests, a so-called outbound proxy server. The use of DHCP is one possible solution for locating the outbound SIP server; the use of specific IP Core Network bearer activation procedures (e.g. PPP in 3GPP2), and manual configuration are other mechanisms. Specifically, the 3GPP2 IP Multimedia Subsystem (IMS) may support either IPv4, IPv6, or both. The SIP Proxy Server (P-CSCF) used in the 3GPP2 IMS may also support either IPv4, IPv6, or both. If, in a 3GPP2 network, it can be assumed that the IP version(s) supported by the P-CSCF is the same as the IP version(s) supported by its associated IMS (and that both the P-CSCF and IMS are owned by and within the same operator's domain), then the mobile can determine if the IMS supports IPv6. It is necessary to use an IPv4 DHCP message to discover an IPv6 SIP Proxy Server as 3GPP2 allows the support of an IPv6 IMS over an IPv4 transport (i.e. the IP version supported by the IMS is independent of the IP version used by the transport (bearer) network). This option expands on the proxy discovery mechanisms provided in RFC 3361. Tacsik Expires August 26, 2004 [Page 3] Internet-Draft DHCP option for IPv6 SIP Proxy address February 2004 2. 3GPP2 IPv6 SIP Server Address Option This DHCP option will return one or more 128-bit (binary) IPv6 address(es) that can be used by the mobile SIP client to locate an IPv6 SIP Proxy Server(s). The return of an IPv6 SIP Proxy Server address is also an indication that the (same) operator's IMS supports IPv6. Unlike the solution provided in RFC 3361, this option has a single encoding to provide only IPv6 addresses. Together with RFC 3361 this option can be used by a mobile SIP client to determine the IP version(s) supported in the operator's IMS. RFC 3361 can be used to discover the IPv4 address of an IPv4 SIP Proxy Server(s) (with enc=1). RFC 3361 (with enc=0) can also be used to discover the Fully Qualified Domain Name (FQDN) of a SIP Proxy Server(s) that, via DNS, can be resoved to be IPv4, IPv6, or both. Description. The 3GPP2 IPv6 SIP Server Address Option has the following format: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Code | Length | 1st IPv6-SIP-Server Addr | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1st-IPv6-SIP-Server Addr (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1st-IPv6-SIP-Server Addr (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1st-IPv6-SIP-Server Addr (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1st-IPv6-SIP-Server Addr (cont)|2nd-IPv6-SIP-Server Addr | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2nd-IPv6-SIP-Server Addr (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2nd-IPv6-SIP-Server Addr (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2nd-IPv6-SIP-Server Addr (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |2nd-IPv6-SIP-Server Addr (cont)| ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Code: TBD - Option code from "Private Use", Site-specific space (128-254) as documented in RFC 2939 Length: This field indicates the total number of octets in the option following the 'Lenght' field. Tacsik Expires August 26, 2004 [Page 4] Internet-Draft DHCP option for IPv6 SIP Proxy address February 2004 1st-IPv6-SIP-Server Addr: the 128-bit IPv6 address of the 1st SIP Proxy server. 2nd-IPv6-SIP-Server Addr: the 128-bit IPv6 address of the 2nd SIP Proxy server. Tacsik Expires August 26, 2004 [Page 5] Internet-Draft DHCP option for IPv6 SIP Proxy address February 2004 3. Security Considerations No new threats are introduced by this proposal. Tacsik Expires August 26, 2004 [Page 6] Internet-Draft DHCP option for IPv6 SIP Proxy address February 2004 4. Intellectual Property Right Notice Nokia has a pending patent application that may be relevant to this draft. Please refer to http://www.ietf.org/ietf/IPR/Nokia for more information. Tacsik Expires August 26, 2004 [Page 7] Internet-Draft DHCP option for IPv6 SIP Proxy address February 2004 References [1] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [2] Droms, R., "Procedures and IANA Guidelines for Definitions of New DHCP Options and Message Types", RFC 2939, September 2000. [3] Schulzrinne, H., Schooler, J. and J. Rosenberg, "SIP: session initiation protocol", RFC 2543, March 1999. [4] Schulzrinne, H., "Dynamic Host Configuration Protocol (DHCP-for-IPv4) Option for Session Initiation Protocol (SIP) Servers", RFC 3361, August 2002. Author's Address Ernie Tacsik Nokia 6000 Connection Drive Irving, TX 75039 Phone: +1(972)894-4044 EMail: ernie.tacsik@nokia.com Tacsik Expires August 26, 2004 [Page 8] Internet-Draft DHCP option for IPv6 SIP Proxy address February 2004 Appendix A. Acknowledgements Tacsik Expires August 26, 2004 [Page 9] Internet-Draft DHCP option for IPv6 SIP Proxy address February 2004 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Full Copyright Statement Copyright (C) The Internet Society (2004). 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. 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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 Tacsik Expires August 26, 2004 [Page 10] Internet-Draft DHCP option for IPv6 SIP Proxy address February 2004 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Tacsik Expires August 26, 2004 [Page 11]