- The Audio Stream (RTP) needs to be captured
- The Call control events needs to be captured(Propriatery PBX protocols or SIP messages)
- Th recording software must have access to both these sets of information while the call is busy
The Recording software detects that a call starts and then sends a copy of the Audio Stream to the recording software. The recording software must then open ports to allow it to capture the information. If you do not configure the IP of the server where the VOIP recording software is running, it doesn't know where to send the audio streams. This will mean that all the call control events will be captured, the ports will be opened, but the actual audio stream will not me sent to the correct IP and so the recording will not take place.