User guide
About the USB Dual Handset Adapter: Keypad Functions
90-00039 3
About the USB Dual Handset Adapter
The 1021 USB Dual Handset Adapter allows 
two people to share a Nortel IP Phone 1100 
Series so they can join in on the same 
telephone call. Capable of supporting any 
combination of two handset or headset 
devices, features of the USB Dual Handset 
Adapter include individual volume, muting, 
and on/off ("exclude") control.
Keypad Functions
The illustration below displays the keys and 
their functions.
Volume Control
Master volume control can be obtained by 
adjusting volume on the IP Phone itself; 
however, best practice is to use the volume 
keys on the USB Dual Handset Adapter. The 
adapter is designed to provide the same 
audio range as the telephone controls when 
the telephone volume remains at the default 
level.
Reserved for future use
Exclude (disables handset or 
headset by muting microphone 
& speaker); Light is ON when 
Exclude Activated
Volume Down (4dB steps)
Microphone Mute; Light is 
ON when Mute Activated
Volume Up (4dB steps)










