JUNHYUK SONG INTERNET DRAFT SAMSUNG ELECTRONICS April 2003 SIP server configuration option for PPP draft-song-pppext-sip-support-02.txt Status of This Memo Distribution of this memo is unlimited. 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 defines a new configuration option for the PPP IPCP (PPP Internet Protocol Control Protocol), to return a list of the IPv4 addresses of SIP proxy servers. This option provides one mechanism that a system may use to locate a SIP proxy server. This approach is applicable for a system that is using PPP for the link layer protocol and IP address allocation. Song Expires October 2003 [Page 1] Internet Draft April 2003 1. Introduction The SIP (Session Initiation Protocol)[3] is a signaling protocol used for the session invitation, modification, and termination. The UAC (User Agent Client) sends a request to the UAS (User Agent Server). However, the request message (INVITE) is not directly sent to the callee UAS, it rather goes through proxy servers and possibly redirect servers. This draft specifyies one mechansim that a system may use to locate a SIP proxy server. This draft specifies an IPCP (PPP Internet Protocol Control Protocol) option that allows SIP clients to locate a list of SIP proxy servers that is to be used for all SIP requests. This approach is applicable to a system utilizing PPP for its link layer protocol and IP address allocation (ex. 3GPP2 Packet Data System) Note: the text defining the format and behavior of these options is quoted from RFC1877 [2], to ensure a consistent implementation. 2. Configuration Options The IPCP Configuration Option format and the basic options are defined in RFC 1332 [4]. This document defines the two new options: Primary SIP Server Address and Secondary SIP Server Address. 2.1. Primary SIP Server Address Option Description This Configuration Option is used for negotiating with the remote peer the address of the primary SIP server Address to be used on the local end of the link. A summary of the Primary SIP Address Configuration Option format is shown below. The fields are transmitted from left to right. Song Expires October 2003 [Page 2] Internet Draft April 2003 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Primary-SIP-Server Address +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Primary-SIP-Server Address(cont)| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type ? [To be assigned by IANA] Primary SIP Server Address Option Length 6 Primary-SIP-Server-Address The four octet Primary-SIP-Server Address is the address of the primary proxy SIP server to be used by the local peer. Setting these four octets to zero requests that the peer provide the address information in a Config-Nak packet. Default No primary server address is provided. 1.3. Secondary SIP Server Address Option Description This Configuration Option is used for negotiating with the remote peer the address of the secondary SIP server Address to be used on the local end of the link. Song Expires October 2003 [Page 3] Internet Draft April 2003 A summary of the Secondary SIP Address Configuration Option format is shown below. The fields are transmitted from left to right. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length |Secondary-SIP-Server Address +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Secondary-SIP-Server Addr (cont)| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type ?+1 [To be assigned by IANA] Secondary SIP Server Address Option Length 6 Secondary-SIP-Server-Address The four octet Secondary-SIP-Server Address is the address of the secondary SIP server to be used by the local peer. Setting four octets are set to zero requests that the peer provide the address information in a Config-Nak packet. Default By default, no secondary SIP address is provided. 3. IANA Considerations Requires IPCP option number assignment 4. Acknowledgements A major portion of the text in this memo was quoted from RFC 1877. Song Expires October 2003 [Page 4] Internet Draft April 2003 References [1] Simpson, W., Editor, "The Point-to-Point Protocol (PPP)", STD 51, RFC 1661, Daydreamer, July 1994. [2] Steve Cobb, "PPP Internet Protocol Control Protocol Extensions for Name Server Addresses" RFC 1877, Microsoft, [3] M. Handley, H. Schulzrinne, E. Schooler, and J. Rosenberg, "SIP: session initiation protocol," Request for Comments 2543, Internet Engineering Task Force, Mar. 1999. [4] McGregor, G., "PPP Internet Control Protocol", RFC 1332, Merit, May 1992. Addresses Questions about this memo can be directed to the authors: JUNHYUK SONG SAMSUNG ELECTRONICS. Packet Technology System Lab. Mobile Development Team Phone: +82-31-279-3639 Email: junhyuk@telecom.samsung.co.kr santajunman@yahoo.com Song Expires October 2003 [Page 5] Internet Draft April 2003 Full Copyright Statement Copyright (C) The Internet Society (2003). 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 ore 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. Song Expires October 2003 [Page 6]