wdiff draft-song-pppext-sip-support-01.txt draft-song-pppext-sip-support-02.txt

JUNHYUK SONG
INTERNET DRAFT SAMSUNG ELECTRONICS
April 2003

SIP server IPCP configuration option for PPP
draft-song-pppext-sip-support-01.txt
draft-song-pppext-sip-support-02.txt

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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.

1. Introduction

The SIP (Session Initiation Protocol)[3] is a signaling protocol
used for the session invitation, modification modification, and termination.
The UAC(User UAC (User Agent Client) sends a request to the UAS(User UAS (User Agent
Server). However, the request message (INVITE) is not directly sent
to the callee UAS, it rather go goes through proxy servers, servers and possibly
redirect servers. This draft is specifying specifyies one mechansim that a
system may use to locate a SIP procy proxy server.

This draft is specifying a 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 the a system utilizing PPP for the its link layer
protocol and IP address allocation (ex. 3GPP2 Packet Data System)

Note :

Note: the text defining the format and behavior of these options are is
quoted from RFC1877 [2] for the sake of [2], to ensure a consistent implementation of PPP. implementation.

2. Configuration Options

The IPCP Configuration Option format and the basic options are
defined by
IPCP configuration option in RFC 1332 [4]. This document concerns defines the following values:

[?] two new
options: Primary SIP Server Address
[?+1] and Secondary SIP Server Address
Address.

2.1. Primary SIP server Server Address Option

Description

This Configuration Option defines a method 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.

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.

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 [To be assigned by IANA] Primary SIP Proxy server) Server Address Option

Length

Primary-SIP-Address

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.
If all Setting
these four octets are set to zero, it indicates an explicit
request 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 defines a method 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.

By default, no secondary SIP address is provided.

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 [To be assigned by IANA] Secondary SIP Proxy server) Server Address Option

Length

Secondary-SIP-Address

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. If all Setting four
octets are set to zero, it indicates an explicit request 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.

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
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