Do not disturb

Do Not Disturb Function The N.E.C key sets have a function so that anyone trying to ring the key set receives a BUSY tone  or routes to voicemail  even if it is not being used. This function is useful if a room is needed for an important meeting and the keyset needs to  be  available  for outgoing calls  but needs to be silent so as not to disrupt the meeting. Pressing the  DND  key then choosing one of the following options does this: 1  -   External calls only 2  -   Intercom calls only 3  –  All calls 0 - Cancel