Paul Kyzivat wrote:
> Dale has covered this. For the original poster, Stefan: there is a lot
> of written information on this subject that you don't seem to be
> familiar with. The most obvious are RFCs 3261 and 3264. For a more
I wonder how I made the impression to not be familiar with 3264, as I
mentioned the requirement from it to increase the o-line version number
if the session is to be modified (8 Modifying the Session):
The offer MAY be identical to the last SDP provided to the other
party (which may have been provided in an offer or an answer), or it
MAY be different. We refer to the last SDP provided as the "previous
SDP". If the offer is the same, the answer MAY be the same as the
previous SDP from the answerer, or it MAY be different. If the
offered SDP is different from the previous SDP, some constraints are
placed on its construction, discussed below.
[...] When issuing an offer that modifies the session,
the "o=" line of the new SDP MUST be identical to that in the
previous SDP, except that the version in the origin field MUST
increment by one from the previous SDP. If the version in the origin
line does not increment, the SDP MUST be identical to the SDP with
that version number.
I would say it makes sense to increase the version in the origin line as
well as apply the other constraints to the modified answer too, but the
text does not really say that, unlike
> complete treatment, see
> http://www.ietf.org/internet-drafts/draft-ietf-sipping-sip-offeranswer-02.txt
where you write in 4.2.5. Subsequent Offers and Answers:
o In the o-line, only the version number may change, and if it
changes it must increment by one from the one previously sent as
an offer or answer. If it doesn't change then the entire SDP body
must be identical to what was previously sent as an offer or
answer.
>
> Once you understand those I think your questions will be answered.
>
> Paul
>
Regards
Stefan Sayer
_______________________________________________
Sip-implementors mailing list
Sip-implementors@lists.cs.columbia.edu
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
