* Support four SIP servers running at the same time .
* Redundancy SIP server Support .
* T.30 ,T.38 Fax Protocol Support .
* NAT,Firewall .
* DHCP client and server .
* Support PPPoE (use for xDSL,cable modem connecting) .
* Support major G7.xxx CODEC .
* VAD,CNG .
* G.165 compliant 16ms echo cancellation .
* E.164 dial plan and customized dial rules .
* Support one for Lifeline .
* Hotline .
* Call Forward,Call Transfer,3-way conference calls .
* Call ID display .
* DND (Do Not Disturb),Black List,Limit List .
* Reverse polarity .
* Voice prompt .