Aastra 55I IP PHONE - RELEASE 2.1 User Manual page 76

2. For softkeys, select from "Key 1" through "Key 20".
or
For programmable keys, select from "Key 1" through "Key 6".
3. In the "Type" field, select Do Not Disturb to apply to the key.
4. If configuring a softkey on the Bottom Keys, in the state fields, check (enable) or
uncheck (disable) the states you want to apply to this softkey.
5. Click
68 Model 55i IP Phone User Guide
to save your changes.