The Emergency Transfer Relay (ETR) feature provides basic telephone services in the event of system failure, such as a power outage or a failed connection to the MGC. ETR services are offered on installed MM714B media modules. When ETR is activated, the G430 connects the MM714B’s trunk port 5 to line port 4. All calls are then directed by the analog relays between the outside lines and the analog telephones. A current-loop detection circuit prevents ongoing calls from being disconnected when normal functioning resumes. If a call is in progress on an outside line when the problem ends, the call continues.The trunk port and analog line port do not start to operate until the active call ends.

You can install an MM714B media module in any slot (1-3, 5-8).When ETR is active and the Branch Gateway has power, the ETR LED is lit.