You can either do a button inquiry in each of the extensions to see which extension number is associated with which name. that is done by going to each set and pressing feature *0 then pressing the intercom key. or you can look through set programming to find out.
Programming is done on 7310, 7324 and 7316 type sets.
Enter programming by pressing the feature key followed by **266344.When prompted to enter the password enter 266344.
The screen should say TERMINALS&SETS. The 4 top line/feature keys are now used for programming.
At the terminals&sets prompt, press the show key (top right arrow).
The display should now ask for an extension number. Press the list soft key.
It will list the extension number followed by the name for the first extension.
Press the next key for the next extension (bottom right arrow) .
Press the release key when finished