- 2 line x 24 character LCD
- 16 programmable call appearance/feature buttons
- Navigation keys for menu, next, previous, and exit
- Fixed feature buttons include conference, transfer, hold, speaker, mute, and redial
- Built-in 2-way speakerphone
- 8 personal ring options
- 4 soft keys for menu functions
- 12 soft key default features with access to 18 alternative soft key features
- The 6416D+ Telephone is compatible with Definity R6.1 or higher and Avaya IP Office.
- It requires an available station port on a TN2181, TN2224/B/CP, IP403/406, IP400 Digital Station 16, or IP400 Digital Station 30.
Avaya Definity 6400 Series User Guide.pdf