Specifications: 1. Operation Frequency: 1.880 - 1.900GHz 2. Power Supply: Handset-Rechargeable Ni-MH battery 2.4VDC,550mAh(2 x 1.2AAA) 3. Operating Time: Standby: Up to 70 hours/Talking :Up to 6 hours 4. LCD display: 2 lies Black & White LCD display (12 alphanumeric, 11 icons) 5. Keys: 19keys 6. Power On/Off fnction 7. Customized handset name 8. Multiple Language User Support(English plus 4 other languages) 9. Handset Key lock 10Visual and Audio low battery warning tone 11Out of range tone(Internal & External) and 5 volume level selection 12Keypad Tone On/Off 13Caller Identity Delivery(CID) 14Call Duration Display(Call Timer) 15CID New Call Indicator on handset 16Phonebook Capabilities(up to 100 records) 17Pre Dialing w/Editing Capabilities 18Call History(u to 20 records) 19Redial Record(up to 20 records) 20TCP/IP: LWIP(LW IP stack version 1.1.0. incl UDP) DHCP-cl(DHCP client) DNS-cl(DNS client, incl Location SIP Server, RFC 3263, DNS extension required for US) TFTP-cl(TFTP client) 21SIP Stack Support: Basic feature - support SIP2.0(RFC 3261 incl INVITE,ACK,BYE,CANCEL, REGISTER UPDATE(RFC3311) INFO(RFC2976) REFER(RFC3515) NOTIFY(RFC3265) MESSAGE(RFC3428) Media Type sipfrag(RFC3420) RFC3489 Support up to 2 SIP accounts active at the same time Support of compressed SIP headers SIP account setting via Ethernet by PC only 22Access via HTTP: Digest Authentication/HTTP pages supports(HTML, Java Script, GIF-picture) Codec Sopport: G.711u,G711a,G.723.1,G.729ab Remark: PSTN is not supported.