The Avaya 9640 IP Telephone is designed for workers who conduct much of their business on the phone moving from one call to the next. It delivers advanced communications capabilities including wideband audio and a brilliant high resolution color display. 9640 IP Telephone Features 3.8" color backlit display 6 line appearances supporting up to 24 call appearances or features 4 softkeys, 4 navigation buttons Built-in full duplex speakerphone Dual message waiting indicators Volume, menu, message, speaker, headset, contacts, and call log buttons Built-in two port Ethernet switch for connection to LAN and collocated PC Supports wideband audio codec Supports up to 3 SBM24 Button Modules for expansion 2 adapter interfaces for add-on support (e.g. 9600 Bluetooth Adapter, 9600 GigE Adapter etc.) Built-in headset interface Requirements and Compatibility IP Office R6.0 or higher only on IP500 and IP500 V2 control units H.323 version supported by Avaya Communication Manager R3.0 or later SIP version supported by Avaya Communication R4.0 or later Powered via 802.3af PoE (Class 2) or local PoE Injector (sold separately)