[SR-Users] CANCEL before INVITE

Klaus Darilion klaus.mailinglists at pernau.at
Tue Jul 6 17:39:24 CEST 2010



Am 06.07.2010 17:04, schrieb Andrei Pelinescu-Onciul:
> On Jul 06, 2010 at 16:55, Klaus Darilion<klaus.mailinglists at pernau.at>  wrote:
>>
>>
>> Am 06.07.2010 16:36, schrieb Andrei Pelinescu-Onciul:
>>> On Jul 06, 2010 at 14:06, Klaus Darilion<klaus.mailinglists at pernau.at>   wrote:
>>>> Obiously the device is buggy.
>>>>
>>>> But there is also on strange thing at Kamailio: it retransmits the
>>>> CANCEL although it has already received 481 response on the CANCEL
>>>> request.
>>>
>>> The first 481 stops the CANCEL retransmissions, however each additional
>>> provisional reply received after that will trigger a one-time CANCEL
>>> retransmission. That's why you see another retransmission after the 481,
>>> it's the "response" to the 180...
>>
>> Cool, nice feature.
>>
>> Unfortunately it doesn't help with David's problem, as the phone
>> obviously does not see the additional CANCEL - probably the phone's
>> transaction layer responds again with 481.
>
> What's strange is that according to the dump it does finally reply with
> a 487, but 8s after it sent a 481 to the last CANCEL:
>
>   <- 100
> CANCEL ->
>   <- 481
>   <- 180
> CANCEL
>   <-481
>   [8s]
>   <-487

True. David, is the 47 sent by the phone autonomously or due to some 
user interaction (e.g. rejecting the call)

regards
klaus



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