RE: [Sip] regarding session modification

Hi,

My concerns:

1. SHOULD the called party reply with 200 OK if the negotiation fails?
2. Why the first two tries to add speechsynth resource failed but the
third success?
3. As my understanding, if the re-negotiation fails, it will not affect
the current media.

Best Regards,

===========================================
Fanwen zhang
FS5000 CPE IOT, Alcatel-Lucent Qingdao, R&D
Tel: +86-532-88615493
Email:fanwenz@alcatel-lucent.com
===========================================

________________________________

From: Srinivas [mailto:srinivasj@huawei.com] 
Sent: Wednesday, January 16, 2008 9:30 PM
To: sip@ietf.org
Subject: [Sip] regarding session modification

Hi all,

Consider the following scenarios. 

1. 

C->S: INVITE (for speechrecog)

S->C: 200 OK

C->S: ACK

Now the SIP session is established b/w UAC and UAS. speechrecog resource
is active on the established sip session

C->S: INVITE (re-INVITE for adding speechsynth resource)

S->C: 200 OK 

Offer/Answer fail for the new resource, TTS (speechsynth).

2. 

C->S: INVITE (for speechrecog)

S->C: 200 OK

C->S: ACK

Now the SIP session is established b/w UAC and UAS. speechrecog resource
is active on the established sip session.

C->S: INVITE (re-INVITE for adding speechsynth resource)

S->C: 200 OK 

Offer/Answer fail for the for the existing ASR(speechrecog) resource
also.

3.

C->S: INVITE (for speechrecog)

S->C: 200 OK

C->S: ACK

Now the SIP session is established b/w UAC and UAS. speechrecog resource
is active

C->S: INVITE (re-INVITE for adding speechsynth resource)

S->C: 200 OK

C->S: ACK

Now both speechrecog and speechsynth are active on the sip session

C->S: INVITE (re-INVITE for removing speechsynth resource)

S->C: 486 BUSY HERE

What should be the behaviour of UAC in the above scenarios?

Regds,

Srinivas