[Users] CANCEL problem

Bogdan-Andrei Iancu bogdan at voice-system.ro
Wed Aug 3 11:29:12 CEST 2005


Hi Michael,

the UAS must notify ASAP the  upstream parties when the INVITE was 
received. Of course, network delays may interfere :(.

If I get it right, you are experience a *FAST* cancel from the UAC 
(since the proxy haven't received the 100 -even if delayed- from UAC). 
Is this the case?

If so, since it's not the fault of any parties, I will try to see if 
there is a way to solve this kind of race.

regards,
Bogdan

Michael Ulitskiy wrote:

>On Tuesday 02 August 2005 06:25 pm, you wrote:
>  
>
>>What is the correct behavior in this scenario?
>>
>>As the proxy didn't received a "100.." yet, it must not send the CANCEL. 
>>IMO it should withhold the CANCEL unless a provisional response is 
>>received, but should stop sending INVITE retransmission.
>>    
>>
>
>I must confess, I didn't read RFC specifically on this subject, but behavior
>you described makes no sense to me. If proxy didn't cancel the call the callee
>keeps ringing forever.
>
>
>  
>
>>Of course this rises the problem that the callee reponses with a 200 OK 
>>instead of a provisional response and then the call can't be cancelled 
>>anymore.
>>    
>>
>
>it's not the case here. UA replies correctly with 100, but a little too late.
>It was my understanding that CANCEL should be forwarded to cancel a call
>regardless of receiving any response. Please correct me if I'm wrong.
>
>  
>




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