Before taking any decision about recording solution
The PBX port should be associated with a monitoring port on which a computer is connected. Then, a trace of the traffic forwarded to the monitoring port should be recorded using the free WireShark tool (http://www.wireshark.org/download.html).
During the time the trace is recorded, different types of calls should be done.
Here are the minimum recording scenarios
- Answer an external call. Ex: answer a call from a cell phone.
- Make an outbound call. Ex: call a cell phone.
- Make an internal call to another extension
- Answer an incoming call, then put it on hold and take it again
- Answer an incoming call, put it on hold, and then transfer it to another extension
- Answer an incoming call and make a conference with another extension and this call
The .pcap file produced can then be analyzed with WireShark (for the major VoIP protocols) to seek the calls made. This will give very useful indications on how the recording solution should be planned.