Metadata

The metadata of the calls will be exposed by making a SIP call through the proxy running on the monitoring server. This is done for all types of calls whether IP or non-IP.

The SIP signalling will include the A-party and B-party information along with the media information such as codec, address, and port on media server where the RTP streams can be captured. The SIP INVITE message contains the CSTA Connection Call ID. This can be used to map the proxy call to the original call.

The proxy SIP call is initiated by sending INVITE to the SIP proxy after the actual call is answered and enters speech state. The INVITE will have A-Party and B-Party information in the From and To SIP Headers respectively. The INVITE SDP will have the media details for one RTP stream direction. The SIP proxy will redirect the INVITE back to the same LIM. The LIM will then reply with 200 OK for the INVITE. The 200 OK SDP will have the Media Details for the other RTP stream direction.

In case of conference call, separate proxy call is initiated for each party in the conference. The call will contain the specific party information along with media details for that party.

The SOM using SIP Proxy feature supports monitoring of traffic when the call is in speech state. Therefore, when the media path of the original call is disconnected because of call hold, the proxy SIP call will be terminated by sending BYE and when the media path re-establishes the proxy SIP call is sent again.