I have an issue when trying to call to a DID number configured in a team's user. Calls are making through an Opensips SBC that I'm configuring. The scenario is as follows:
Microsoft client (DID number) <--> Microsoft SIP server <--> SBC <--> Calling part
The problem is that when I make a call to the DID number, the teams app picks up the call but at the same time, starts a new one to the telephone number where the call comes from. The signalization between my SBC and the Microsoft Server is ike this:
Microsoft server <-- Invite -- SBC
Microsoft server -- 180 --> SBC
Microsoft server -- 183 --> SBC
Microsoft server -- 200 --> SBC (when picks up the call, generates a new one)
The audio starts and audio is clear between both sides but after 20 seconds the call hangs up and at "Call history" on teams, the call is shown as a "missed call".
I'm not sure what is wrong on my side but not able to see anything from teams side as the whole communication is all over TLS.
Is there something that I need to fix on the RTCP offer, how can I troubleshoot this?
Any suggestion is more than welcome.