Asterisk is not adding Via field

Hi,

 

     I am trying to integrate asterisk with openser for a simple call. I am facing some issues with Asterisk. Below is the explanation:

 

 

      I have a UA1 sending invite to UA2 through Openser and Asterisk with the below sequence.

     Sequence is UA1->OpenSER->Asterisk->Openser->UA2

      When Asterisk gets the INVITE, the INVITE contains two Via headers, one of the UA1 and the other Openser217;s. As Asterisk acts as a B2BUA, it recreats the Dialog.           So before forwarding the INVITE to Openser back, it is removing the Via header of UA1 and also it is not adding its own Via header. So when the INVITE reaches UA2 from Openser, the INVITE will have only one Via header (which is of Openser). So when UA2 responds with 180 Ringing, it will reach Openser, but Openser cannot forward to Asterisk because it does not contain the Via header of Asterisk.

 

 

Please help me out.

 

Cheers,

-Sandeep A