AW: [Users] Declined INVITE invokes multiple Decline's at Proxy

[Bogdan-Andrei Iancu]

Hi Andrew,


Augustin, Andrew (external) wrote:

>Hello Daniel,
>
>Thank you very much for your tips. 
>
>You are right. The ACK did not match the dialog - under this particular scenario there was an inconsistency between the branch, to, and from tags. 
>
>Hello All, 
>
>I have further questions related to this topic and routing of 'locally generated' ACKs...
>
>-  How does OpenSER distinguish between 'locally generated' and 'end-to-end' ACKs?
>
>  
>
end-to-end ACKs are matched based on transaction matching against the 
INVITE transaction (see the RFC for the transaction matching elements).

for hop-by-hop ACKs, additional info as top most via and RURI as 
required to identically match the INVITE transaction.

>-  How does OpenSER know when a 'locally generated' ACK closes the transaction (e.g. Decline reply) that it is involved in? 
>
>  
>
by matching the ACK against the INVITE transaction.

>-  Does openser allow the modification of the Route header in a 'locally generated' ACK and usage of TM's t_relay method to relay this ACK? Or is this prohibited so that only OpenSER is allowed to automatically route locally generated ACKs? 
>  
>
hop-by-hop ACK routing is not based on Route - actually this requests 
does not contain any Route hdr

regards,
bogdan

>Best regards,
>Andrew 
>
>
>
>-----Ursprüngliche Nachricht-----
>Von: Daniel-Constantin Mierla [mailto:daniel at voice-system.ro] 
>Gesendet: Mittwoch, 12. Juli 2006 16:32
>An: Augustin, Andrew (external)
>Cc: users at openser.org
>Betreff: Re: [Users] Declined INVITE invokes multiple Decline's at Proxy
>
>
>Hello,
>
>seems that the ACK does not match the dialog, thus the decline reply is 
>retransmitted. The network trace (ngrep) will help to spot more.
>
>Which of Proxy-1..3 is OpenSER and how the INVITE is routed? looking at 
>the reply path, A seems to talk directly with proxy 2, but it is not 
>right since the decline reply is sent back to A from Porxy 1. Or you 
>didn't presented the full trace?
>
>Cheers,
>Daniel
>
>
>On 07/12/06 14:26, Augustin, Andrew (external) wrote:
>  
>
>>Hello,
>>
>>I am using openser v1.0.
>>
>>I have a problem with the following SIP scenario with openser:
>>
>>- A invites B to a call session, B declines the invitation
>>
>>The message trace shown below is just part of the message trace
>>produced for the above scenario displaying message frames in sequence 
>>F43, F44 ... through F64
>>
>>Initially everything works as expected: INVITEs, Trying (100) and
>>Ringing 180 messages are routed correctly from A to B and from B to A 
>>via the intermediate proxies (this is not shown below). While still 
>>'Ringing', B decline's the call (sends a Decline message) message: F44 
>>in trace below. This also initally routes OK.
>>
>>
>>But the call flow for this scenario is expected to terminate at
>>message: F55 once the 'Decline' has routed its way back from the 
>>B-Party to the A-Party and a final 'ACK' is sent by the A-Party to the 
>>previous proxy: Proxy-1.
>>
>>But what actually occurs is that openser running on Proxy-1
>>automatically resends a 'Decline' at message F56 identical to the 
>>'Decline' it first sent at message F46. This in turn prompts further 
>>ACKs and 'Decline's until it finally times out at message F107 (not 
>>shown below).
>>
>>It appears that openser saves the original message and attempts to
>>retry/resend the 'Decline' message when prompted by an ACK. This 
>>continues for several cycles with ACKs and Decline's being sent and 
>>received around the system until a timeout occurs.
>>
>>
>>The above behaviour also occurs for the following scenario:
>>
>>- A invites B to a call session, B responds with a Busy
>>
>>Can you help me to:
>>
>>- understand what is going on
>>- terminate what appears to be an open 'transaction' for the 'Decline'
>>and prevent further 'Decline's and ACKs being sent around the system.
>>
>>Best regards,
>>Andrew
>>
>>
>>_______________________________________________
>>Users mailing list
>>Users at openser.org http://openser.org/cgi-bin/mailman/listinfo/users
>>  
>>    
>>
>
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>