Let me clarify,

I'm implementing the transaction and the application layer.  How  
would I go about timing out the session on the UAS side?
On Mar 4, 2007, at 1:53 AM, [EMAIL PROTECTED] wrote:

> Daniel Corbe wrote:
>> Hello,
>>
>> RFC3261 defines how transactions should be handled.  It clearly   
>> defines the role of a "client" transaction and a "server"   
>> transaction.  The "client" transaction is required to start  
>> request  timers T1 and T2.  T1 is a retransmission timer and T2 is  
>> a lifetime  timer.  T2 is always 64*T1 (which allows for 7  
>> retransmissions before  the session is to be torn down)
>>
>> My question is as follows:
>>
>> In the server transaction (meaning I'm receiving the request),  
>> should  I start T2?
>
> No.  Since we are under the assumption that the UAS has received  
> the INVITE, it would imply that the UAS has sent a "100 Trying"  
> back to the UAC which would kill the Time A (Retransmission Timer)  
> and Timer B( Timeout Timer).
>
>
>>  I would expect to receive a CANCEL back from the UA  after T2 has  
>> fired.
>
> I think you got confused along the way.  T2 should have been  
> terminated by your initial "100 Trying" response.
>
>
>>   If I haven't received this CANCEL I'm going to  want to tear the  
>> session down so it doesn't waste space in my  transaction pool.
>>
>
> The UAS transaction shouldn't participate in tear down while in the  
> proceeding state.  If an application defined timeout occurs, it is  
> the responsibility of the application layer to feed the transaction  
> unit with a "408 Request Timeout".   The transaction then changes  
> state to "completed state and start Timer G to retransmit the error  
> response until Timer H fires or an ACK is received.  It is only at  
> this point you that you can tear down your transaction.
>
>
>> If this sounds appropriate, what value should I use for T2?  If I  
>> use  the RFC-specified 64*T1 I would expect that there's a  
>> possibility of  the UA's cancel coming in while or after I have  
>> torn the session down.
>>
>> What's a good amount of time to allow the UA to send the CANCEL   
>> before just blindly tearing the session down.
>>
>> -Daniel
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>

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