Performance and features Support h.323 v4, compatible with most h.323 v1-v4 system and devices Built in h.323 proxy support to pass nat Support mgcp rfc2705 Support sip rfc2543 Support net2phone private protocol Fast start and h.245 tunneling Outband dtmf transmit by h.245 user input or q.931 keypad IEEE 802.3/802.3 u 10 base t/100base tx Major g.7xx and gsm610 audio codec Caller ID send and receive by q.931 Provide direct IP address to IP address call mode, direct pstn call by a voice gateway, e.164 phone number call under the mode of gk Automatically gatekeeper discovery in LAN Call pstn by itsp\'\'s prepaid card(etalkitalk, ringtec etc) Dhcp support for automatically assign IP address and others relevant parameters Pppoe support for ADSL or cable modem Setting IP net phone parameters by standard web browser(suchas ie6.0), phone keypad or standard telnet Upgrade program by ftp mode; Support g.723.1 5.3k/6.3k, g.729, g.711 a-law, u-law audio codec algorithm Dynamic voice detection; echo cancellation; comfort noise generation Dynamic voice jitter buffer which minimize effect to the voice caused by the audio delay and jitter and as a result the quality of voice is high; Tone generation and local dtmf generation and detection according with itu-t E.164 dial plan and customized dial rules 40 entries each for missed call, answered call and dialed call 112 entries for quick dial 16 entries for voice message LCD display dial data, caller name, caller number and so on Working status indicating lamps(red, yellow and green) and keypad jacklight Independently digit adjust the volume of handset, hand free 14 function keys for operating and setting phone besides standard keys 0-9, # Speed dialing Adjustable volume for both handset and speaker 16 function keys, background LED and states indicating lights Settings by HTTP web browser(ie60); Advanced settings by telnet Voice prompt Upgrade by tftp.