Features: 1) Radius based CDR for accounting 2) STUN client for NAT transversal 3) Flexible interface for analog phones, fax, traditional PBX with analog trunks 4) Main applications: a) Remote SIP access gateway for IP-PBX b) IP based wide area PBX for enterprise, government branches and schools c) VoIP long distance application for IP phone supermarkets and enterprises d) Carrier primary and secondary line service e) Small and home offices 5) In conjunction with soft switch or IP-PBX servers, can provide the following features: a) Fax and modem service b) GY8 series supports fax tone detection and codec bypass (T.30), and fax relay (T.38) function 6) Supports protocols codec: G.711, G.723.1, G.729A, G.168 echo cancellation a) Session Initiated Protocol (SIP)) b) Media Gateway Control Protocol (MGCP) c) Real Time Transport Protocol (RTP) d) TFTP for remote software upgrade e) HTTP for system and interface configuration and monitoring f) SNMP v.1, v.2, v.3 g) Telnet for remote support h) DHCP for dynamic IP address allocation i) DTMF j) STUN Client for NAT/firewall traverse k) Caller ID l) Message waiting indication m) Call waiting n) Call forwarding o) Caller id on call waiting p) Call transfer (on busy, no answer, all) q) Special purpose calling codes r) Speed dial s) Redials 7) DTMF transportation: transparent mode, RFC 2833 mode, SIP / INFO mode 8) Fax: transparent mode (T.30), fax relay mode (T.38) Specifications: 1) Power 5V / 3A DC power supply (included with AC adaptors) 2) Power dissipation: 15W (max.) 3) Talk battery: 24V 4) Ringing voltage: 50V RMS 5) Loop current: 21mA 6) Max. line length: 1,500m or 415ohm 6) REN equivalence: 5 for short loop (1,000 feet), 3 for long loop (5,000 feet) 7) Analog interface: RJ-11 8) Off-hook detection loop start 9) Dialing DTMF 10) Memory: 32MB 11) Flash: 8MB 12) Dimensions (L x W x H): 195 x 118 x 34mm 13) Weight: 650g