| Status: |
SIMPLE WG Item, draft -01. Long history. |
| Date of last update: |
June 30, 2003 |
| Authors: |
B. Campbell, J. Rosenberg, R. Sparks, P. Kyzivat |
| Current Document: |
draft-ietf-simple-message-sessions-01.txt |
| Summary: |
The SIP MESSAGE method is used to send instant messages, where each
message is independent of any other message. This is often called
pager-mode messaging, due to the fact that this model is similar to
that of most two-way pager devices. Another model is called
session-mode. In session-mode, the instant messages are part of a
media session that provides ordering, a security context, and other
functions. This media session is established using a SIP INVITE, just
as an audio or video session would be established.
This document describes a The Message Session Relay Protocol (MSRP),
a mechanism for transmitting session-mode messages with minimal relay
support. Additionally, this document describes using the SDP offer/
answer model to initiate such sessions.
|
| Archive of older drafts: |
- The first proposal for IM sessions was July 13, 2001. It consisted of
a draft on the general session concept,
draft-ietf-simple-im-session-00.txt and an SDP extension for doing it, draft-ietf-simple-im-sdp-00.txt. The actual messages in the session were sent using the SIP MESSAGE request.
- There was pushback on using SIP MESSAGEs for IM sessions. So, along
with Avshalom Houri (Lotus) and Christian Huitema (Microsoft), we wrote
a proposal called the IM Transport Protocol (IMTP), draft-rosenberg-simple-im-transport-00.txt
which was not SIP, but looked and behaved exactly like it, except for removal
of a bunch of features that were in the way of MESSAGE being good for
sessions.
- There was pushback on the IMTP concept. It felt like a hack. So,
I went back and revisited the decision to use a separate protocol. Based
on enhancements in RFC 3261, I argued that MESSAGE was a reasonable
approach. This was documented in draft-rosenberg-simple-message-session-00.txt, which
isued May 2, 2002.
- On October 25, 2002, two drafts were released,
draft-campbell-simple-im-sessions-00.txt and
draft-campbell-simple-cpimmsg-sessions-00.txt, which took a different tact.
They defined baseline message transport using CPIM.
- The basic CPIM approach needed a bit more beef to satisfy requirements.
Particularly, it needed mechanisms for error handling and dealing with
intermediaries. So, it was expanded into a "shim" kind of protocol meant
for carryign MIME e2e. That is
draft-campbell-simple-im-sessions-01.txt, issued March 2003.
|