[sr-dev] uac dialog callback and kamailio restarts

[Henning Westerholt]

Hi Daniel,

I meant with "should  working" - if it is not working then it is either 
a bug or a (not known) current limitation of the uac implementation. :-)

Cheers,

Henning

Am 10.04.19 um 09:29 schrieb Daniel-Constantin Mierla:
> Hello,
>
> well, to be clear, I do not know if it should work for uac, I haven't
> used replace from/to with dialog so far. But I remember I saw in the
> past some code/discussions related to callbacks at startup when loading
> database records from dialog table.
>
> Cheers,
> Daniel
>
> On 10.04.19 09:05, Henning Westerholt wrote:
>> Hi Daniel,
>>
>> thank you, will have a look to the cnxcc module, good hint. Good to know
>> that it should working even after a restart.
>>
>> Cheers,
>>
>> Henning
>>
>> Am 10.04.19 um 08:56 schrieb Daniel-Constantin Mierla:
>>> Hello,
>>>
>>> I had in mind to check the code and be sure, but I forgot about it ...
>>> so, I think there is already a callback function that is executed by
>>> dialog module when loading records from database. Maybe uac module is
>>> not registering itself for it, or does it too late. Just look at what
>>> callbacks dialog exports, eventually see cnxcc module to see if it does
>>> something on this regard -- it depends on dialog and I expect it works
>>> also after restarting.
>>>
>>> Cheers,
>>> Daniel
>>>
>>> On 10.04.19 08:41, Henning Westerholt wrote:
>>>> Hello,
>>>>
>>>> any comments on this?
>>>>
>>>> Thanks and regards,
>>>>
>>>> Henning
>>>>
>>>> Am 05.04.19 um 17:03 schrieb Henning Westerholt:
>>>>> Hello,
>>>>>
>>>>> I am working right now on another difficult topic related to the usage
>>>>> of uac dialog callbacks for the usual replace from/to header logic
>>>>> after a kamailio restart.
>>>>>
>>>>> The uac/dialog module combination works just fine - but after a
>>>>> kamailio restart the dialog callback information is lost. So this
>>>>> means that for already established dialogs no from/to replacement
>>>>> operations are done. This causes errors later on during BYE or
>>>>> Re-INVITE signalization.
>>>>>
>>>>> I verified this with debug logging and can easily test this on a test
>>>>> system.
>>>>>
>>>>> One obvious workaround is of course not use the dialog module to store
>>>>> the data inside dialog variables.
>>>>>
>>>>> An approach to work on this problem would be to store the uac callback
>>>>> in the dialog table(s) as well, and then during kamailio startup use
>>>>> this to re-install the uac callback.
>>>>>
>>>>> Does this approach sounds feasible? Any other ideas how to tackle this
>>>>> issue?

-- 
Henning Westerholt - https://skalatan.de/blog/
Kamailio services - https://skalatan.de/services