[SIPForum-discussion] Passing several 2xx responses to servertransaction

[Yevgen Krapiva]

Thanks guys !!!
It's now clear.

2009/5/4, Tomasz Zieleniewski <tzieleniewski at gmail.com>:
> Hi again,
>
> Well in this case this more an implementation specific question.
> You must keep in mind that in INVITE transaction if the response is 200 OK
> then ACK is not considered part of the INVITE transaction and that is why
> transaction passes into terminated state.
> Because of the importance of delivering 200 OK response,
> it is periodically passed directly to the transport and sent until ACK
> arrives.
> If there is finally no ACK session is considered confirmed by should be
> immediately
> terminated with BYE.
>
> Proxy and UAC behavior with 200 OK response is different and
> this is the reason why it is not handled in the transaction layer.
> UAC just retransmitts ACK, proxy whenever it's transport layer receives a
> responses
> and there is no matching to a client transaction, passes responses directly
> to the core
> this case a proxy core. After that proxy core forwards response upstream
> towards UAC statelessly.
>
> Kind regards,
> Tomasz
>
>
> 2009/5/2 Yevgen Krapiva <ykrapiva at gmail.com>
>
>> Thanks for reply.
>> But actually, I was asking about how to send more than one 2xx
>> response over single
>> invite server transaction ? The diagram of INVITE server transaction
>> shows that once you sent 2XX response, the transaction goes into
>> terminated state.
>> This means, as I understand, that if I (proxy) need to say UAC that
>> there is another one 2XX response, I need to send this one
>> statelessly, beacuse initial server transaction is already terminated.
>>
>> Am I right ?
>>
>> 2009/5/2, Giscard Fernandes Faria <GISCARDF at nec.com.br>:
>> > YKrapiva,
>> >
>> > Once a request is forked by a proxy, more than one response will be
>> > received for the same request. However the UAC is not the one whom
>> > receive all those
>> > responses; the Proxy whom forked the request will receive them.
>> >
>> > What SIP RFC stands, is that those responses shall be merged in a
>> > unique
>> > one
>> > for non-INVITE request (the best response of all shall be picked).
>> > However
>> > when the request was an INVITE all responses shall be delivered to main
>> > UAC;
>> > this is necessary so UAC can open a distinct dialog for each 2XX
>> > response or
>> > event kill early dialogs for each 4xx-6xx response
>> >
>> > Hope this can help.
>> >
>> > Regards
>> >
>> >
>> >
>> > Giscard Fernandes Faria-  Software Engineering Department
>> > NEC Brasil S.A.
>> > Phone +55 11 2166-2713 * Mobile + 55 11 8561-0710
>> > "There are no 'cookbook' methods that can replace intelligence,
>> > experience, and good taste in design and programming", Bjarne
>> > Stroustrup
>> > giscardf at nec.com.br
>> >
>> >
>> > -----Mensagem original-----
>> > De: discussion-bounces at sipforum.org
>> > [mailto:discussion-bounces at sipforum.org] Em nome de Yevgen Krapiva
>> > Enviada em: sexta-feira, 1 de maio de 2009 10:30
>> > Para: discussion at sipforum.org
>> > Assunto: [SIPForum-discussion] Passing several 2xx responses to
>> > servertransaction
>> >
>> > Hi.
>> >
>> > I need clarification on the following quote from RFC 3261, Response
>> > processing in statefull proxies:
>> >
>> >>Step 5. Check response for forwarding
>> >>...
>> >>This step, combined with the next, ensures that a stateful
>> >>proxy will forward exactly one final response to a non-INVITE
>> >>request, and either exactly one non-2xx response or one or more
>> >>2xx responses to an INVITE request.
>> >
>> > How can I pass several responses over single server transaction ?
>> > If I pass only one then transaction state will be changed to
>> > terminated.
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>