The AT-640P is a user friendly, multi-line IP phone that supports both SIP and IAX2 with 4 double colour LED indicators and 4 soft-keys. It is compatible with many standard SIP and IAX2 soft switches and IP PBX systems.

Specifications
Hardware
- 128 x 64 dot matrix
- Wall mountable
- Full duplex speaker
- MWI: Mono-colour x 1
- Line keys: Bi-Colour x 4
- BLF Keys: Bi-Colour x9 (Maximum 49 keys with 2 EX20 module)
- Voicemail LED: Mono-Colour x 1
- Headset LED: Mono-Colour x1
- Mute LED: Mono-Colour x 1
- Speaker LED: Mono Colour x 1

Interfaces
- WAN x1
- LAN x1
- RJ9 handset Jack x1
- RJ9 headset Jack x1
- Power jack x1

Electric requirements
- Voltage: 9V ~ 24V
- Power adapter: output DC 12V/500 mA

Operating requirement
- Operating temperature: 0~40ºC
- Storage temperature: -30~65ºC
- Humidity: 10~90% no dew

VoIP
- SIP (SIP RFC3261, RFC 2543)/ IAX2 support
- 4 SIP lines + 1 IAX2 line
- Redundancy sip server capability
- Hotline
- Call Forward, Call transfer, Call hold, Call waiting, 3-way talking, Pickup, Join call, Redial, Unredial Call Park, vport, click to dial
- DND(Do Not Disturb)
- Black List, Limit List
- E.164 dial plan and customised dial rules
- SMS, Voice-mail, BLF
- Supports POE