Basic Call Flow

After Party A and Party B are connected and a recording request is made to SIP Server, SIP Server will initiate two sessions, one session for each party, to Media Server. SIP Server first INVITEs with the Session Description Protocol (SDP) offer from the connected parties to Media Server, and a second reINVITE to Media Server to get an SDP offer from Media Server. The offer from SIP Server is sent to the connected parties to proxy the media through Media Server. Once the media is established, Media Server initiates the media stream replication process and sends an INVITE to the recording server through Resource Manager. Depending on the configuration of the recording server, there are two ways to establish the recording session:

• Two sessions—One SIP recording session representing each participant in the call, meaning Media Server will initiate two INVITE requests to the recording server.
• One session—One SIP recording session containing all the media streams of both participants in the call.

The following diagram describes the call flow: