100 Extensions Video Calls Multiple Language DID(Direct Inward Dialing Number) Support SKYPE for SIP Call Monitor / Record FXO to FXS life line Codec: G.711-Ulaw,G.711-Alaw,G.726,G.729,GSM,SPEEX,H.261,H.263,H.263+,H.264 Call Hold / Forward / Transfer / Waiting / Parking Call Paging and Intercom Caller ID Music On Hold DISA(Direct Inward System Access) Flexible Dial Plan Ring Group Conference Room Black List Phone Book Call Queue BLF(Busy Lamp Field) Built-in SIP/IAX2 server Build-in voice mail server Echo Cancellation/VAD Configuration By web Configuration by SSH Support Static/DHCP/PPPOE VPN Server/Client DDNS(Dyndns.org /No-ip.com /zoneedit.com) Support NTP(Network Time Protocol) Auto-provisioning