[Users] ACK is sent before the re-INVITE to OpenSER, but the proxy relays the re-INVITE first (call flow in the body).

[Klaus Darilion]

IMO the receiving client should be tolerant and accept the reINVITe 
although the ACK is missing/delayed, as the reINVITE is an implict ACK.

regards
klaus

Bogdan-Andrei Iancu wrote:
> Hi Alexandre,
> 
> if I'm not wrong ,this topic was previously discussed on the mailing 
> list. The idea is that openser cannot guarantee that messages will be 
> sent in same order as received. And this because of parallel 
> multi-process execution.
> 
> the idea is that the CC1 shouldn;t send a re-INVITE so fast and also the 
> GW should wait a little bit to see if ACK is delayed or not.
> 
> if you are running in full debug, the logs will might help you to see 
> how the ACK and INVITE gets swapped during processing.
> 
> regards,
> bogdan
> 
> Alexandre Abreu wrote:
> 
>> Hello. 
>> Below it's the call flow.
>>
>>
>>    UAC          CALL CONTROL 1      OPENSER 1            GW
>>     |                |                |                |
>>     |   INVITE F1    |                |                |
>>     |--------------->|                |                |
>>     |     100  F2    |                |                |
>>     |<---------------|   INVITE F3    |                |
>>     |                |--------------->|                |
>>     |                |     100  F4    |                |
>>     |                |<---------------|     INVITE F5  |
>>     |                |                |--------------->|
>>     |                |                |     183 F6     |
>>     |                |     183 F7     |<---------------|
>>     |     183 F8     |<---------------|                |
>>     |<---------------|                |                |
>>     |                |  Early Media   |                |
>>     |<==============>|<===============|================|
>>     |                |                |      200 F9    |
>>     |                |    200 F10     |<---------------|
>>     |                |<---------------|                |
>>     |                |                |                |
>>     |                |     ACK F13    |                |
>>     |                |--------------->|                |
>>     |                |  re-INVITE F14 |               |
>>     |                |--------------->|                |
>>     |                |                | re-INVITE F15  |
>>     |                |                
>> |--------------->|                    |                
>> |                |   ACK  F16     |
>>     |              |                |--------------->|     
>> |                |                |                |
>>     |                |                |    500 F17     |
>>     |                |                | <--------------|
>>     |                |                |                |
>>
>>
>> The problem is between F13 and F16. Why OPENSER relays the re-INVITE 
>> first
>> (F15), if the ACK (F13) was sent before and arrives before?
>> And I am sure that this ACK hits a t_relay(), because after the re-INVITE
>> sent, the ACK (F16) is sent normally...
>>
>> I am using OpenSER 1.0.1.
>>
>> Any help is appreciated.
>>
>> Alexandre
>>
>>
>>
>>
>>
>> _______________________________________________
>> Users mailing list
>> Users at openser.org
>> http://openser.org/cgi-bin/mailman/listinfo/users
>>
>>  
>>
> 
> 
> _______________________________________________
> Users mailing list
> Users at openser.org
> http://openser.org/cgi-bin/mailman/listinfo/users