Performance and features
    Support SIP,IAX2 protocol
    DHCP support for LAN or Cable modem
    Audio codec G.711,G.729,GSM,iLBC
    Blue back light
    CALL WAIT,HOLD,TRANSFER supported
    Set by HTTP web browser (IE6.0) or Telnet
    Upgrade by FTP,TFTP or HTTP
    VAD(Voice active detect)
    CNG (Comfort noise generation)
    G.168/165 compliant 16ms echo cancellation
    Dynamic voice jitter buffer
    Network interface:1/2 RJ-45 Ethernet connectors