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

[Alexandre Abreu]

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