Interfaces: 1 X WAN 1 X LAN Voice Features: Support SIP (RFC3261 RFC3262 RFC3265) Codec: G. 711A/u, G. 7231 high/low, G. 729 Echo cancellation: Support G. 168, and Hands-free can support 96ms Full duplex hands-free speakerphone Support Voice Gain Setting, Jitter Buffer, VAD, CNG NAT transverse: Support STUN client SIP support SIP domain, SIP authentication (none, basic, MD5), DNS name of server, Peer to Peer SIP support Pubic & Private server. Can connect to ISP and Private SIP server at the same time DTMF: Support SIP info, DTMF Relay, RFC2833 SIP application: Support Call forward/transfer/holding/waiting Call control features: Flexible dial map, support Hotline, Empty calling No. Reject service, Black list for reject authenticated call, No disturb, Caller ID. Support conference call and voice record English, Spanish, Czechoslovak alternative Network Features: WAN/LAN: Support Bridge and Router model Support basic NAT and NAPT Support PPPoE for xDSL Support DHCP Client on WAN Support DHCP Server on LAN Support DNS Relay, SNTP Client, Firewall Network tools in telnet server: Including ping, trace route, telnet client Maintenance and Management: Support Boot Monitor Can upgrade firmware through boot monitor Can config through Web, keypad, Telnet Can upgrade firmware and configuration file through HTTP, FTP, TFTP Support Syslog Certifications: CE, FCC, RoHS Certified