RE: [SWMP] What is the relationship of SWMP to SIP and/or XMPP?

Just to be clear:

We are planning to enable XMPP integration for the chat and presence, just
not 3D state sharing because of the particularly demanding requirements.

Tony

  _____  

From: Jay C. Weber [mailto:jweber@mediamachines.com] 
Sent: Wednesday, June 13, 2007 8:18 PM
To: john_patterson@us.ibm.com
Cc: swmp@ietf.org
Subject: Re: [SWMP] What is the relationship of SWMP to SIP and/or XMPP?

john_patterson@us.ibm.com wrote: 

Although SIP (really SIMPLE) and XMPP were designed for "buddy list" like
awareness.  They do define a low latency state sharing mechanism with a
"buddy list"-specific pub-sub model.  At first blush it would seem sensible
to ask whether the transport layers for SIP and/or XMPP are serviceable for
SWMP and, if so, focus attention on the virtual world-specific pub-sub
model. 

Hi John, a very good question.  I argued with myself over using XMPP for
some time.  In the end, like most multiuser-3D implementors I believe, I
decided that bandwidth efficiency is just too important (much moreso than
for chat) to not have a packed binary protocol, especially over the fairly
inefficient ascii encoding of XML as required by XMPP.  A similar situation
to why, to my knowledge, nobody uses XML encodings to stream audio or video.

That is, I reluctantly turned away from XMPP as an encoding for
position-data streams.  As I understand it, XMPP is an application protocol
so it doesn't specify transport layers to adopt, except in the sense that
people usually carry XMPP over TCP, and SWMP does use TCP as transport (as
well as UDP).

I know SIP/SIMPLE less well, but I do understand that SIP is an application
protocol and likewise built on top of the standard transports.  Interesting
idea though to use SIP to establish the sessions, or similarly, for SWMP to
subsume SIP messaging.  I'll definitely look into that.

jay
--
Jay C. Weber
CTO, Media Machines