FV6020 is a kind of voice communication terminal which is based on wide band and independent of PC (personal computer). *Support H323v4 and SIP RFC3261 synchronously; *Support Codec:G.711,G.723.1,G.729; *Echo cancellation: Support G.168,and Hands-free can support 96ms; *Support Voice Gain Setting, Jitter Buffer, VAD,CNG,H323 support dual GK, call forward, and Peer to Peer. *NAT transversal: Support STUN client,AVS and Citron etc. Can modify SIP register port,HTTP server port,Telnet server port and RTP port *Support two SIP server synchronously: Can register two different SIP server,and can make a call by either proxy *Provide easy configuration thru manual operation (phone keypad,Web interface and Telenet) or automated centralized configuration file via TFTP or HTTP *Support firmware upgrade via TFTP&FTP and HTTP