JUNHYUK SONG
INTERNET DRAFT DAEJOONG KIM
June 2002 SAMSUNG ELECTRONICS
SIP server IPCP configuration option for PPP
draft-song-pppext-sip-support-00.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
The Point-to-Point Protocol (PPP) [1] provides a standard method for
transporting multi-protocol datagrams over point-to-point links.
PPP defines an extensible Link Control Protocol (LCP) for
establishing, configuring, and testing the data-link connection; and
a family of Network Control Protocols (NCPs) for establishing and
configuring different network-layer protocols.
This document defines the PPP IPCP configuration option that contains
a list of IPv4 addresses of SIP proxy servers. It is just one of the
many possible mechanism to locate the SIP proxy server, such as DHCP
option [6] and manual configuration. This approach is applicable to
the system using PPP for the link layer protocol and IP address
allocation (ex. 3GPP2 Packet Data network)
Song and Kim Expires December 2002 [Page 1]
Internet Draft June 2002
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 go through proxy servers, and possibly
redirect servers. This draft is specifying one of the many possible
mechanism to locate the SIP proxy server, such as DHCP option[6] and
manual configuration.
This draft extends the NCP for establishing and configuring the
Internet Protocol over PPP [4], by specifying a IPCP 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 the
system utilizing PPP for the link layer protocol and IP address
allocation (ex. 3GPP2 Packet Data network)
Note : the format and behavior of these options are quoted from
RFC1877 [2] for the sake of consistent implementation of PPP.
2. Configuration Options
The Configuration Option format and basic options are defined by
IPCP configuration option [4].
The most updated value of the IPCP Option Type field are specified in
the IANA web site [IANA-ALLOCATION]. This document concerns the
following values:
[?] Primary SIP Server Address
[?+1] Secondary SIP Server Address
2.1. Primary SIP server Address Option
Description
This Configuration Option defines a method for negotiating with
the remote peer the address of the primary SIP server Address
to be used on the local end of the link.
By default, no primary SIP server address is provided.
A summary of the Primary SIP Address Configuration Option format is
shown below. The fields are transmitted from left to right.
Song and Kim Expires December 2002 [Page 2]
Internet Draft June 2002
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
? (Primary SIP Proxy server)
Length
6
Primary-SIP-Address
The four octet Primary-SIP-Server Address is the address of the
primary proxy SIP server to be used by the local peer.
If all four octets are set to zero, it indicates an explicit
request that the peer provide the address information in a
Config-Nak packet.
Default
No address is provided.
1.3. Secondary SIP Server Address
Description
This Configuration Option defines a method for negotiating with
the remote peer the address of the secondary SIP server Address
to be used on the local end of the link.
By default, no secondary SIP address is provided.
Song and Kim Expires December 2002 [Page 3]
Internet Draft June 2002
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 (Secondary SIP Proxy server)
Length
6
Secondary-SIP-Address
The four octet Secondary-SIP-Server Address is the address of the
secondary SIP server to be used by the local peer. If all four
octets are set to zero, it indicates an explicit request that the
peer provide the address information in a Config-Nak packet.
Default
No 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 and Kim Expires December 2002 [Page 4]
Internet Draft June 2002
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.
[5] H. Schulzrinne and J. Rosenberg, "SIP: Session initiation
protocol -- locating SIP servers," Internet Draft, Internet
Engineering Task Force, Mar. 2001. Work in progress.
[6] H. Schulzrinne "DHCPv4 Option for SIP Servers" Internet Draft,
Internet Engineering Task Force, Mar. 2001. Work in progress.
[IANA-ALLOCATION] Internet Assigned Numbers Authority,
http://www.isi.edu/in-notes/iana/assignments/multicast-addresses.
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
DAEJOONG KIM
SAMSUNG ELECTRONICS.
Packet Technology System Lab.
Mobile Development Team
Phone: 82-31-279-3625
EMail: daejoong@samsung.com
Song and Kim Expires December 2002 [Page 5]
Internet Draft June 2002
Full Copyright Statement
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 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 and Kim Expires December 2002 [Page 6]