Many recorders in the market place are of Analogue design and as such cannot record the new generation of IP telephone systems.
The only solution was to pick up the audio signals from the handset.
This has many disadvantages, some off which are:
Large analogue signal loss.
Hum and Noise pick up.
User able to disconnect audio.
Often hands free calls not recorded.
All wiring not-contained in secure equipment room.
No CLI or Dialled Number
DAC INTERFACE TYPE IP10:
Universal interface for IP telephones and equipment using SIP and H323 channel type transmission standard.
CLI and Dialled number (if available) output as DTMF
Highest possible sound quality.
From built in codex G711, G723, GSM
. Other codex (G726, G729, Speex, iLBX) available.