>>Interesting, never thought about it. So, if I send a re-INVITE for
>>which I have no final reply yet and then I send a BYE, should the UAS
>>reply 200 for the BYE and terminate the remaining re-INVITE
>>transasction without sending a final response?

>>Or should the UAS reply a "491 Request Pending" for the BYE? Anyhow
>>section 14.2 in RFC 3261 just indicates that 491 is useful when there
>>is a pending re-INVITE from A to B and B sends a re-INVITE to A. In
>>that case A should reply 491.
A re-INVITE must not be forked, as RFC says in section 14. Then, no BYE might 
come for a re-INVITE. The BYE shall be understood in order to finish the dialog 
itself. The CANCEL must be used in that case.



>> The unique transaction which remains is the BYE transaction for sending 
>> another 200 OK for some retransmission.
>>
>>
 Although, the UAC may send some final response (i.e. 487) before 
sending the 200 OK for the BYE. In matter fact, there is some 
homologating procedures which requires this behaviour.

>If the BYE is supposed to "magically" terminate all the pending
>transactions within the dialog (without requiring a final response for
>them) then I see no reason to send a 487 (maybe it would fail as the
>UAC would already terminate the client transaction for the initial
>INVITE).

As the BYE terminates all transactions, it not really necessarilly. However, it 
is desired to send the final response in order to avoid retransmissions or 
unexpectable behavour . I think that's why some homologating procedures 
requires that. Sending the final response (i.e.487) before 200 OK is reliable. 

 
Leonardo


________________________________
De: Iñaki Baz Castillo <[email protected]>
Para: Leo Leo <[email protected]>
Cc: "[email protected]" 
<[email protected]>
Enviadas: Quarta-feira, 27 de Julho de 2011 9:03
Assunto: Re: [Sip-implementors] BYE before call answer

2011/7/27 Leo Leo <[email protected]>:
> Anyway, the RFC says that a receiving BYE must to finish all transactions of 
> the associated dialog.

Interesting, never thought about it. So, if I send a re-INVITE for
which I have no final reply yet and then I send a BYE, should the UAS
reply 200 for the BYE and terminate the remaining re-INVITE
transasction without sending a final response?

Or should the UAS reply a "491 Request Pending" for the BYE? Anyhow
section 14.2 in RFC 3261 just indicates that 491 is useful when there
is a pending re-INVITE from A to B and B sends a re-INVITE to A. In
that case A should reply 491.


> The unique transaction which remains is the BYE transaction for sending 
> another 200 OK for some retransmission.
>
> Although, the UAC may send some final response (i.e. 487) before sending the 
> 200 OK for the BYE. In matter fact, there is some homologating procedures 
> which requires this behaviour.

If the BYE is supposed to "magically" terminate all the pending
transactions within the dialog (without requiring a final response for
them) then I see no reason to send a 487 (maybe it would fail as the
UAC would already terminate the client transaction for the initial
INVITE).


Interesting topic :)

Regards.





-- 
Iñaki Baz Castillo
<[email protected]>
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