Mitel 5020 IP User Manual page 10

Handling Calls with a Headset (no Feature Control Switch):
To answer a call (when Auto Answer is disabled):
Press the flashing Line Select key.
To hang up:
Press CANCEL.
Handling Calls with a Headset with Feature Control Switch:
To answer a call (when Auto Answer is disabled):
Quickly press and release the Control Switch.
To mute the headset microphone (Headset with Feature Control Switch only):
Press and hold the Control Switch.
To hang up:
Quickly press and release the Control Switch.
6