Hi
I have one query regarding timers handling in 491 "Request Pending" for
Re-Invite.
The scenario is like this:
A call is being established with an Application which is behaving as B2BUA. Now
we receives Reinvite from both sides- UAC and UAS at same time and due to which
a glare situation arises and B2BUA sends 491 "Request Pending" to both sides
UAC and UAS. So my query is that: what should be the value of Retry-After timer
in 491 for both call legs?
INVITE ----------> B2BUA ----------> INVITE
100 <---------- B2BUA <---------- 100
183 <---------- B2BUA <---------- 183
200 <---------- B2BUA <---------- 200
ACK ----------> B2BUA ----------> ACK
<------------Call Established---------->
REINVITE-------> B2BUA <-------REINVITE
491 <---------- B2BUA ----------> 491 (What should be the value of
Retry-After timer in 491 response on both sides?)
As per RFC-3261, I got this information:
"If a UAC receives a 491 response to a re-INVITE, it SHOULD start a
timer with a value T chosen as follows:
1. If the UAC is the owner of the Call-ID of the dialog ID
(Meaning it generated the value), T has a randomly chosen value
between 2.1 and 4 seconds in units of 10 ms.
2. If the UAC is not the owner of the Call-ID of the dialog ID, T
has a randomly chosen value of between 0 and 2 seconds in units
of 10 ms."
But since in case of B2BUA, is it that we should check if it is side-1, then
timer value should be 2-4 seconds and if it is side-2, then timer value should
be 0-2 seconds.
Is this correct understanding or anybody having some other views on this?
Regards,
kamini gangwani
Aricent
________________________________
"DISCLAIMER: This message is proprietary to Aricent and is intended solely for
the use of the individual to whom it is addressed. It may contain privileged or
confidential information and should not be circulated or used for any purpose
other than for what it is intended. If you have received this message in
error,please notify the originator immediately. If you are not the intended
recipient, you are notified that you are strictly prohibited from using,
copying, altering, or disclosing the contents of this message. Aricent accepts
no responsibility for loss or damage arising from the use of the information
transmitted by this email including damage from virus."
_______________________________________________
Sip-implementors mailing list
Sip-implementors@lists.cs.columbia.edu
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
