The Aastra 55i IP phone includes up to 9 lines support, 6 soft keys with LEDs, programmable up to 20 functions, 6 programmable keys with LEDs, graphical 144x75 pixel LCD screen, White LED backlight, full duplex speakerphone, dual 10/100 switched Ethernet ports, headset support with built-in amplifier, PoE and AC adapter, Flash programming, and expandable up to 3 modules of model 536M.