... function Support VAD, CNG, EC--------------------------------------------------------------------------------Key Features Open Standard VoIP Protocols (ITU H.323 V4 and IETF SIP V2) ... WAN, PC, GSM Call forward from GSM to VoIP and VoIP to GSM Dial in mode or dial out mode only ... in or dial out Retransmit GSM Caller ID to VoIP terminalEnhanced Features Dynamic selection of codec Advanced jitter buffer ...