Hello All,
We have a B2BUA server which needs to support a particular call
flow.
The initial set up call flow is as shown
CALLER B2BUA CALLEE1 CALLEE2
|--------INVITE(SDP1)-->| | |
| |-------INVITE(SDP1)--->| |
| |<--------180(SDP2)-----| |
|<-------180(SDP2) -----| | |
| |<---------4xx ---------| |
| |----------ACK----------| |
| |-------INVITE(SDP1)------------------->|
| |<------180(SDP3)-----------------------|
| | |
The flow here is of sequential routing wherein if one user is not responding
then the next number configured has to be tried until one person answers.
But as you can see the issue with the flow is that the 180 with SDP3 cannot
be forwarded to the caller directly.
As per rules of RFC 3261,3262 as I understand when a reliable provisional
response contains a session description, and is the first to do so, then
that session description is the answer to the offer in the INVITE request.
SDP should not be included in the subsequent 1xx-rel once offer/answer has
been completed.
Due to this we cannot refresh the SDP to the caller. Even use of UPDATE
would result in a race condition.
Please let me know if there is a solution to update the SDP( SDP3) on the
caller side. Is there any other way of handling this situation?
Thanks and Regards,
Umesh
****************************************************************************
***********
This e-mail and attachments contain confidential information from HUAWEI,
which is intended only for the person or entity whose address is listed
above. Any use of the information contained herein in any way (including,
but not limited to, total or partial disclosure, reproduction, or
dissemination) by persons other than the intended recipient's) is
prohibited. If you receive this e-mail in error, please notify the sender by
phone or email immediately and delete it!
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
