Support two SIP servers running at the same time

              Redundancy SIP server support

              NAT,Firewall

              DHCP client and server

              Support PPPoE (used for ADSL,cable modem connceting

              Support major G7.xxx CODEC

              VAD,CNG

              G.165 compliant 16ms echo cancellation

              E.164 dial plan and customized dial rules

              Hotline

              Call Forwaard,Call Transfer,3-way conference calls

              Call ID display

              DND (Do Not Disturb),Black List,Limit List