Specifications

G150 Media Gateway
Issue 6 February 2007 111
Operation in survivable mode
In survivable mode, a G150 Media Gateway uses the parameters that the system administrator
administers in the G150 administration interface. These parameters, which must match as
closely as possible those established on the Communication Manager server, include the
following features:
● Dial plan
● Trunk access codes
● System parameters
● Feature assignments
In survivable mode, the G150 allows locally connected endpoints to:
● Call other locally-connected endpoints
● Make and receive external calls over the public network.
● Use the following features:
- Called List Identification (CLI) and Automatic Number Identification (ANI)
-Hold
- Transfer
- Call waiting indication
- Last number redial
- Drop call
In addition, G150 Media Gateway assumes control of the front panel LEDs of the G150 Media
Gateway. As a result, G150 LED indications in survivable mode differ from those when the
G150 Media Gateway is under control of the remote server.
While in survivable mode, incoming calls that go to voice mail coverage connect to the G150
voice mail cache. The G150 Media Gateway uses this cache to capture and store voice
messages. Service to the media server running Communication Manager is restored. Then, the
G150 Media Gateway forwards the messages to the server’s central messaging system (for
example, Modular Messaging). Users can then get their messages.
Return of control to server
In survivable mode, the G150 Media Gateway can continue to support calls indefinitely.
However, while in survivable mode, the G150 Media Gateway attempts to reregister with the
remote server according to administered time intervals. When the G150 Media Gateway
successfully reregisters with the remote server, the G150 Media Gateway exits survivable
mode. The G150 relinquishes call processing control to the remote server. The G150 forces the
local endpoints to also reregister with the remote server. Active calls are preserved when call
processing control returns to the remote server. When the call is completed, any endpoint that is
on an active call reregisters with the remote server.