Subject: [Sip] When does "Re-INVITE" take effect ?

From: [email-masked]
Date: Wed, 23 Jul 2003 21:58:11 +0900

Hello,
 
If IP/port in SDP changes, when does "Re-INVITE" take effect ?
 
from Sip-Implementors mail archive
http://lists.cs.columbia.edu/pipermail/sip-implementors/2001-May/001211.html
<http://lists.cs.columbia.edu/pipermail/sip-implementors/2001-May/001211.htm
l> 
 
from RFC3312
Integration of Resource Management and Session Initiation Protocol (SIP) 
13. 1 End-to-End Status Type
http://www.zvon.org/tmRFC/RFC3312/Output/chapter13.html
<http://www.zvon.org/tmRFC/RFC3312/Output/chapter13.html> 
 
from RFC3264 
An Offer/Answer Model Session Description Protocol
8.3.1 Modifying Address, Port or Transport
http://www.zvon.org/tmRFC/RFC3264/Output/chapter8.html
<http://www.zvon.org/tmRFC/RFC3264/Output/chapter8.html> 
 
        Alice                Proxy 2                Bob 

           |      Both Way RTP Media Established     | 

           |<=======================================>| 

           |                                         | 

           |           Bob changes IP address        | 

           |                                         | 

           |                 F9 INVITE               | 

           |<----------------------------------------| 

           |                F10 200 OK               | 

           |---------------------------------------->|   

           |                 F11  ACK                | 

           |<----------------------------------------| 

           |         New RTP Media Stream            | 

           |<=======================================>| 

1) In above flows, 

Alice may continue sending media to Bob's old address during "Re-INVITE".

Alice may start sending media to Bob's new address 

before sending 200 OK, if "Re-INVITE" is accepted by Alice.

Bob may continue sending media to Alice during "Re-INVITE" ?

Am I right ?

2) If RTCP timeout occurs on Alice and there is no active media session with
Bob, 

does Alice terminate SIP session with Bob ?

3) If Bob sends RTCP with new SSRC and new address before "Re-INVITE" is
accepted by Alice, 

is there any problem in that ?

Thanks in advance.

Brad Park