Message Waiting Indication (MWI)

Some PBX Private Branch Exchange - telecommunication system systems offer a feature called Message Waiting Indication (MWI) which is used to signal to the user that there is a new voice mail or text message available. Usually this condition is signaled by a light on the user's telephone. Some telephones also provide a button near the indicator light that allows to display the new text messages or dials into the voice mail system in order to listen to new voice messages.

PBX Private Branch Exchange - telecommunication system systems with MWI features offer an interface that allows external voice mail systems to turn on and off the MWI lights. The most common method (and the only method that TERAVoice supports) is to have the voice mail system dial a certain number in order to control the MWI lights.

Example for SIEMENS HiCom/HiPath:

Turn on MWI light: '7568%0'

Turn off MWI light: '7668%'

Where '%' is the extension number of the station that is to be controlled.
Please note: For SIEMENS systems this method only works if the station that is calling the code is configured as 'Voice Mail'.

Please consult the documentation of your PBX Private Branch Exchange - telecommunication system system for more information on how to set up MWI with other models.