The Do Not Disturb or (DND) function on most
PBX or
PABX
A business telephone system is a multiline telephone system typically used in business environments, encompassing systems ranging in technology from the key telephone system (KTS) to the private branch exchange (PBX).
A business telephone syst ...
systems prevents calls from ringing on an
extension
Extension, extend or extended may refer to:
Mathematics
Logic or set theory
* Axiom of extensionality
* Extensible cardinal
* Extension (model theory)
* Extension (predicate logic), the set of tuples of values that satisfy the predicate
* Ext ...
for which DND is activated. Some Do Not Disturb (DND) attributes include directing the call to a preassigned extension (like a secretary or assistant), busy signal, DND signal, or recorded message generated by the telephone switch. Some switches allow the call to go through to the extension but restrict the response to a visual indication. Some PBX systems allow the assignment of DND circumvention codes to supervisors.
The implementation of this feature is vendor-specific. In some cases, the ringer just does not ring and the called party is thus not alerted. Usually, though, the phone just acts as being busy. Depending on the infrastructure, the caller may end up on the called party's
voice mailbox
A voicemail system (also known as voice message or voice bank) is a computer-based system that allows users and subscribers to exchange personal voice messages; to select and deliver voice information; and to process transactions relating to ind ...
, sometimes after a certain delay.
Some special configurations combine DND with other features like
call forwarding
Call forwarding, or call diversion, is a telephony feature of all telephone switching systems which redirects a telephone call to another destination, which may be, for example, a mobile or another telephone number where the desired called party i ...
, where calls to a party with DND on are forwarded to another phone.
References
Mitel 3300 Integrated Communications Platform(page 15)
Calling features
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