Subject: [Sip] Multi-Media SIP Scenario

From: Purcell Michael-QA3001 <[email-masked]>
Date: Wed, 5 Dec 2001 08:48:52 -0700

I cannot discover from the existing standards or drafts if the following Multi-Media Scenario is to the SIP Standard:

Successful SIP to SIP with two Media

   User A          Proxy 1/User B    User C
     |                |                | 
     | INVITE(M1,M2)  |                | 
     |--------------->|    User B      |
     |                |--| Setup       |
     |                |<-|  M1         |
     |     OK(M1)     |                | 
     |<---------------|  INVITE(M2)    |
     |     ACK(M1)    |--------------->|    User C
     |--------------->|                |--| Setup       
     | RTP Media M1   |                |<-|  M2
     |<==============>|    OK(M2)      | 
     |     OK(M2)     |<---------------|
     |<---------------|                |        
     |     ACK(M2)    |                |
     |-------------------------------->|
     |                |                |
     |        RTP Media M2             |
     |<===============================>|

In this scenario, there are two media streams (M1, M2) connecting User A to from two separate sources User B and User C. From User As perspective, both media streams could be originating from the same source. 
  So the INVITE goes out asking for both media streams. The Proxy and User B are co-located. User B forwards an INVITE for M2 to User C through it's proxy interface and returns the OK for just M1. A Separate OK message for M2 is returned from User C to User A. The ACK for the second media stream (M2) bypasses the proxy.

		Thanks Mike Purcell

_______________________________________________
Sip mailing list  http://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [email-masked] for questions on current sip
Use [email-masked] for new developments on the application of sip