100 Meridian Digital Telephone IP Adapter Installation and Administration Guide
Using the digital telephone Standard 1.1
Indicator updates
Digital telephone indicators reflect the current status of the telephone. For
example, they identify when calls are waiting, active, on hold, or (if your office
has voice mail) that messages are waiting.
The host PBX updates indicators when a connection between the host PBX and
Meridian Digital Telephone IP Adapter unit is active.

Host-controlled indicator updates

The host PBX automatically updates indicators for host-controlled features each
time any of the following occur:
!the host PBX receives an incoming call from your site
!the host PBX processes an outgoing call from your site
!the host PBX sends a message waiting indicator (MWI) update
Note: When online with a permanent conne ct ion to the host PBX, a remote site
receives constant telephone indicator updates.