Q1: How to record phone calls in VOIP environment?
There are 2 ways of doing it.
TAP the IP traffic at SWITCH using Port mirroring, collect the IP traffic & convert to sound file. This is called passive recording
the recording application will be an active medium between telephone & IPPBX. This is called Active recording. This method is costlier than passive and which include hardware unit. Dialog records IP calls using passive approach which is purely software oriented. No hardware required. It works well with Cisco, Avaya, Nortel, SIP & Asterisk.