Subject: [dispatch] charter proposal: SIP end-to-end Session Identifier

From: Salvatore Loreto <[email-masked]>
Date: Mon, 23 May 2011 09:49:44 +0300

Hi there,

below a charter proposal for a new wg working on End-to-end Session 
Identifier in SIP.

In an effort to make progress and to facilitate the discussion
we have also created an Internet Draft that captures, at a high level,
the requirements and use cases.
(It was submitted by Paul E. Jones last Friday; here the link:
http://www.ietf.org/id/draft-jones-ipmc-session-id-reqts-00.txt )

cheers
/Sal

End-to-end Session Identifier in SIP (charter proposal )
----------------------------------------------

The end-to-end Session Identifier in an SIP-based multimedia 
communication refers to the ability
for endpoints, intermediate devices, and management and monitoring 
system to identify
and correlate SIP messages and dialogs of the same higher-level 
end-to-end "communication
session" across multiple SIP devices and hops.

Unfortunately, there are a number of factors that contribute to the fact 
that the current
dialog identifiers as defined in SIP is not suitable for end-to-end 
session identification.
Perhaps the most important factor worth describing is that in real-world
deployments devices like Session Border Controllers (SBC) often change 
the current call
identifiers (e.g., the From-tag and To-tag that are used in conjunction 
with the Call-ID header
to make the dialog-id) as the session signaling passes through.

An end-to-end Session Identifier should allow the possibility to 
identify the communication session
from the point of origin, passing through any number of intermediaries, 
to the ultimate point
of termination. It should have the same aim as the From-tag, To-tag and 
Call-ID conjunction,
but should not be mangled by intermediaries.

A SIP end-to-end Session Identifier has been consideredas possible 
solution of different use cases like
troubleshooting, billing, session tracking, session recording, media and 
signaling correlation, and so forth.
Some of these requirements have also been identified and come directly 
from other existing
working group within the RAI area (e.g. SIPRec, Splices).

Moreover, otherSDOs have identified the need for SIP and H.323 to carry 
the same "session ID" value(s)
so that it is possible identify a call end-to end even when performing 
inter working between
protocols.

This group will first focus on adocument that will identify, collect and 
discuss all the
requirements and the use cases that have been identified.
The document may identify the possibility to design a general mechanism 
or the need
to design multiple purpose built identifiers.
Once the needs are clear and identified, the working group will specify 
the mechanism(s).

Specifically, the proposed working group will develop the following 
deliverable:

   1. A requirement and use case document with key consideration for SIP
      Session
      End-to-End identifier. The document will discuss the possibility
      of designing
      a general mechanism or the needs to design multiple purpose build
      identifier.
   2. Specification of new mechanism(s).

Goal and Milestone:
     October 2011 - Requirement and use case document sent to the IESG 
(Information)