[OpenSIPS-Users] Transfer issue

[Bogdan-Andrei Iancu]

Hi Iñaki,

Iñaki Baz Castillo wrote:
> El Lunes, 16 de Noviembre de 2009, Bogdan-Andrei Iancu escribió:
>   
>> I agree that a b2bua is more complex than a proxy, but I guess the idea 
>> is to identify all these buggy cases and fix them.
>>     
>
> A very important issue in most of the existing B2BUA's:
>
> Imagine the b2bua routes/generates the call to a proxy which does parallel 
> forking so b2bua receives two 183 with different To-tag and, of course, 
> different SDP (sess-id, sess-version...).
>
> The b2bua replaces the received To-tags in an *unique* new To-tag to be used 
> in the upstream leg.
>
> This is a bug since the UAC will receive two 183 with same To-tag but 
> different SDP so it must ignore the second SDP (a SDP cannot change during an 
> early-dialog).
>   
are you sure about this behaviour ? is it stated by  RFC3261?
> I've issued this problem. The solution is "easy":
>
> For each received 1XX response (different To-tags) the b2bua must create so 
> many different To-tags for the 1XX it sends to the UAC.
>
> If the b2bua doesn't replace the To-tag then the problem automatically 
> dissapears, but then it's not a b2bua :)
>   
it does change :)

Regards,
Bogdan


-- 
Bogdan-Andrei Iancu
www.voice-system.ro