Uttam Kumar Sarkar wrote:
> How about the forking case when B2BUA is forking the INVITE to multiple
> contacts of B. Each of then ( PhB1, PhB2 and PhB3) sent 183 with SDP. Of
> course those 3 SDP ( received in the order SDP_B1, SDP_B2 and SDP_B3)would be
> from 3 different dialog. Now PhB3 sends 200 OK with SDP.
> How the B2BUA is going act on receiving different answers?
The B2BUA can handle3 this in a couple of ways:
- it can hide the forking entirely. To do this it may have to act as a
media relay, and perhaps a transcoder.
- it can act like a forking proxy to PhA. In that case it will establish
an early dialog with PhA for each early dialog it establishes with one
of the other phones.
Paul
P.S. including the sip forum on the dist list is a problem for those of
us not permitted to post there.
> |-----------
> PhA------------->| B2BUA |---------->PhB1
> | |---------->PhB2
> | |---------->PhB3
> ------------
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Somesh S
> Shanbhag
> Sent: Thursday, July 20, 2006 8:17 AM
> To: Markus Hofmann
> Cc: [email protected]; Manpreet Singh; [EMAIL PROTECTED]
> Subject: Re: [Sip-implementors] [SIPForum-discussion] Offer in a 200OK
> forInvite transaction.
>
>
> Hi Markus,
>
> I think the expected behavior from UAS is it MUST not include two different
> SDP's in 18x(non-reliable) and 200 responses.
>
> But if it does that also section 13.2.1 of RFC 3261 mentions UAC to ignore
> the answer in 200 when it has received the answer in 18x (non-reliable).
>
> Thanks
> Somesh S. Shanbhag
>
> Markus Hofmann <[EMAIL PROTECTED]> wrote: Hi Somesh,
>
> I have question related to this.
>
> What is the right behaviour (sending out INVITE with SDP offer) if SDP in 18x
> (non-reliable) and 2xx are different? Sending ACK / BYE? Ignoring 2xx SDP?
>
> Regards
> Markus
>
> Somesh S Shanbhag wrote:
>> Hi Manpreet,
>>
>> RFC 3261 section 13.2.1 has the following clause ...
>>
>> "
>>
>> If the initial offer is in an INVITE, the answer MUST be in a reliable
>> non-failure message from UAS back to UAC which is correlated to that
>> INVITE. For this specification, that is only the final 2xx response
>> to that INVITE. That same exact answer MAY also be placed in any
>> provisional responses sent prior to the answer. The UAC MUST treat
>> the first session description it receives as the answer, and MUST
>> ignore any session descriptions in subsequent responses to the initial
>> INVITE
>> "
>>
>> So, UAC MUST treat 183 session progress as the answer and shall ignore
>> in subsequent responses to INVITE.
>>
>> Hope this helps
>> Thanks
>> Somesh S. Shanbhag
>>
>>
>>
>> Manpreet Singh wrote: For the INVITE transaction where the
>> offer was sent in an INVITE and the answer coming back in 183, would it be
>> valid to send a new offer in the 200OK? So the question is whether the
>> 200OK can be used to send a "new" Offer ( different from the answer in 183
>> ) for the INVITE transaction once 183 has completed the offer/answer part
>> of that transaction. Only UPDATE can be used for early dialog changes as
>> per my understanding and a 200OK still constitutes early dialog so it wont
>> be valid to send a new offer in 200OK? Although 200OK can carry the same SDP
>> as 183 which would mean nothing or would not be considered as early dialog
>> change in capability.
>>
>> Please correct me if I am wrong.
>>
>> Thanks
>>
>> Manpreet
>> _______________________________________________
>> discussion mailing list
>> [EMAIL PROTECTED]
>> http://sipforum.org/mailman/listinfo/discussion
>>
>>
>>
>> -----------------------------------------
>> SIMPLICITY IS THE BEAUTY.
>> BE NATURAL LIVE NATURAL.
>> -----------------------------------------
>> Somesh S. Shanbhag
>> Focus Area - VoIP Team (FA-VoIP)
>> Mascon Global Communication Technologies
>> Enterprise of Mascon Global Limited
>> #59/2, 100Ft Ring Road
>> Banashankari II stage
>> Bangalore-560070
>> Karnataka
>> INDIA
>> Website: http://www.mgl.com/
>> -----------------------------------------
>>
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>
>
>
> -----------------------------------------
> SIMPLICITY IS THE BEAUTY.
> BE NATURAL LIVE NATURAL.
> -----------------------------------------
> Somesh S. Shanbhag
> Focus Area - VoIP Team (FA-VoIP)
> Mascon Global Communication Technologies
> Enterprise of Mascon Global Limited
> #59/2, 100Ft Ring Road
> Banashankari II stage
> Bangalore-560070
> Karnataka
> INDIA
> Website: http://www.mgl.com/
> -----------------------------------------
>
> ---------------------------------
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