Grandstream Networks GXP21 Series

Figure 11: GXP2170 Keyboard
Figure 12: GXP2135 Keyboard
Contacts. Press to view and edit contact information.
Hold. Press to put call on hold or resume the call.
Mute. Press to mute or unmute the call.
Headset. Press to switch to headset mode.
Message. Press to view voicemail messages.
Transfer. Press to transfer call.
Conference. Press to conference call.