Avaya T3 (IP) Comfort - Manual (Page 108)

Changing general settings
108
Customizing the telephone
Extended call display
You can set your telephone to always display not only the caller’s number or name
but the number which they dialled.
This tells you whether the caller wants to speak to service or the workshop, for
example.
Press the "Menu" function key.
Scroll to the Settings menu item.
Confirm selection.
Scroll to the Applications menu item.
Confirm selection.
Scroll to the Call display A->B menu item.
Confirm selection.
Exit menu. The setting is saved.