> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
> Sent: Saturday, March 24, 2001 5:36 AM
> To: [EMAIL PROTECTED]
> Subject: [Sip-implementors] Doubt in SDP Negotiaiton for RE-invite
>
>
>
>
>
> Assume the following callflow.
>
> 1)INVITE/OK/ACK happens between UserA and User B for codec as PCMU.
> 2)User A sends a re-INVITE with the codec supported as LPC. User B
> sends a 200OK with support for LPC. Meanwhile User A's codec
> support was
> changed to GSM.
If that is the case, why did a re-invite indicating LPC? Are you saying it
changed again after the re-INVITE?
> 3) User A finds that it no more supports the negotiated media.
> What does the User A do with this?
> Should the User A respond with ACK to the 200OK and send a
> re-invite for
> the new media (OR)
> Should User A drop the 200OK responses as it no more
> supports the codec
> and User B might be sending
> media on that port after it receives an ACK from User A.
Once again, the fundamental mantra of sip:
all transactions complete independently
all transactions complete independently
all transactions complete independently
so, the re-invite should be ACKed, and then another re-invite immediately.
Doesn't seem that likely that a phone would all of a sudden be unable to
support the codec it has been using. I think re-invites will usually be to
change IP addresses and ports for media, in support of services.
-Jonathan R.
---
Jonathan D. Rosenberg 72 Eagle Rock Ave.
Chief Scientist First Floor
dynamicsoft East Hanover, NJ 07936
[EMAIL PROTECTED] FAX: (973) 952-5050
http://www.cs.columbia.edu/~jdrosen PHONE: (973) 952-5000
http://www.dynamicsoft.com
_______________________________________________
Sip-implementors mailing list
[EMAIL PROTECTED]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
