Yes; see RFC 4566 section 5.2.

"<sess-version> is a version number for this session description.  Its
usage is up to the creating tool, so long as <sess-version> is
increased when a modification is made to the session data."

> -----Original Message-----
> From: [email protected] [mailto:sip-
> [email protected]] On Behalf Of Amit Kumar
Singh
> Sent: Wednesday, April 08, 2015 5:23 AM
> To: [email protected]
> Subject: [Sip-implementors] Regarding o line version number increment in
SDP
>
> We are facing an issue where the UAC send a Re-Invite with modified SDP
as an
> offer(a=sendonly), the UAS replies it with a answer containing the
previous
> SDP o line version number but with a modified attribute
line(a=recvonly).
>
>
>
> Please find the detailed Scenario:
>
> 1.  UAC<->UAS (call is established)
>
> 2.  UAC-------->UAS(Re-Invite with a=sendonly)
>
> 3.  UAC<--------UAS(200 Ok with same SDP o line version number as
present in
> 1 but with a=recvonly)
>
>
>
> As per RFC 3264 section 6 "If the answer is different from the offer in
>    any way (different IP addresses, ports, etc.), the origin line MUST
>    be different in the answer, since the answer is generated by a
>    different entity.  In that case, the version number in the "o=" line
>    of the answer is unrelated to the version number in the o line of the
>    offer."
>
>
>
> So is it mandatory for the UAS to increment the o line version number in
the
> response of the Re-Invite?
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors

Reply via email to