What is MWI?

A message -waiting indicator(MWI) in telephony, is a Telcordia Technologies(formerly Bellcore) term for an FSK-based telephone calling feature that illuminates an LED on select telephones to notify a telephone user of waiting voicemail messages on most North American public telephone networks and PBXs.

As described in Telcordia Generic Requirements Requirements document GR-283, a message waiting_indicator(MWI) is a mechanism that informs the subscriber about the status of recorded messages.

The subscriber may subscribe to a notification feature that makes use of the status of this MWI.

What is VMWI?

 

A VMWI(visual message waiting indicator), as defined in Telcordia GR-1401-CORE, is a stored program controlled switching(SPCS) system feature that activates and deactivates a visual indicator on customer-premises equipment(CPE) to notify the customer that new messaes are waiting. VMWI differs from existing features that use other message indicators, such as audible stuttered dial tone, in that it activates a visual indicator on the CPE. The visual indicator may be as simple as lighting or flashing a light-emitting diode(LED), or as advanced as displaying a special message on a liquid-crystal display(LCD).

 

All the Flyingvoice gateway series of products support both MWI and VMWI function.