Features Support SIP 2.0 (RFC3261) and correlative RFCs Codec:G.711A/u, G.7231 high/low, G.729, G.722 Echo cancellation: Support G.168, and Hands-free can support 96ms, Hand free Speaker Phone Support Voice Gain Setting, VAD, CNG Full duplex hands-free speakerphone NAT transverse:support STUN client SIP support SIP domain, SIP authentication (none, basic, MD5), DNS name of server, Peer to Peer/ IP call SIP support 4 Pubic 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, Hotline, Empty calling reject, Black list for reject authenticated call, limit call, No disturb, Caller ID. Support three way conference call Support voice record, 240 seconds max or 3 record max, user-defined record prompt with 1 minute max Support Phonebook 500 records Incoming calls / Outgoing calls / Missing calls. Each support 100 records. Support conference and voice record on SIP server 8 kind of ring type 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 VLAN (optional: voice vlan/data vlan) QoS with DiffServ Support DMZ Support VPN (L2TP/UDP TUNNEL) Support DNS Relay, SNTP Client, Firewall Network tools in telnet server: Including ping, trace route, telnet client   Maintenance and Management Web ,telnet and keypad management Management with different account right Upgrade firmware through POST mode Upgrade firmware through HTTP, FTP or TFTP. Telnet remote management./ Upload/download setting file Safe mode provide reliability Supoort Auto Provisioning (upgrade firmware or configuration file) Support Syslog Standard Component: Item JR-904 Adapter(Input/Output)   WAN 10/100Base- T RJ-45 for LAN LAN 10/100Base- T RJ-45 for PC Power Consumption Idle:1.5W active:1.8W LCD size 3 in.(70 x 33mm) Operation Temperature 0～40°C Relative Humidity 10～65% Main Chipset INFINEON IFX21553(MIPS32:150M,DSP:100M) SDRAM 64Mbits Flash 16Mbits Dimension(W×H×D) 11.6×8×3 in.(295×205×75mm) Weight 2.07lb.(0.94kg) alternative PoE(Power Over Ethernet),Headset   Standard Component: Item Qty Remarks Phone 1 LCD Display, Keypad Adaptor 1   CD 1 User Manual Ethernet PortRJ45 2   Cable N/A   Packing: Inner box MEAS 260655mm G.W./unit 1.08kg Carton MEAS 5500575mm G.W. 11kg PCS/CTN 10pcs