NM-HDA Power fail Phones

Unanswered Question
Jun 4th, 2009

Can somebody please confirm the operation of Power Fail Phones (Red Phoes) on the NM-HDA.

Our install would like PSTN Line connected to MGCP Controlled FXO Port to trigger a Hunt Pilot Point.

Upon power failure of the Router calls should be sent to an analogue Phone using FXO power failure.

Reading the documentation Im not sure that this can be achieved.

regards

Ian.

I have this problem too.
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irisrios Wed, 06/10/2009 - 13:24

The FXO Power Failure feature is a hardware feature that is built into the FXO cards. The feature allows connectivity to an analog phone that is patched into the right pair of wires to be activated by a relay if power to the router that contains the NM-HDA fails.

If router power drops and the NM-HDA goes down with the router, then there is a relay on the NM-HDA that connects the FXO (CO trunk) to a "red phone" (an otherwise unused wire pair in the cable) to enable emergency calls to the PSTN during a power outage. This is known as FXO power-fail switchover. The NM-HDA is the only one of FXO HW cards that has this capability.

High-Density Analog Telephony Network Modules:

http://www.cisco.com/en/US/docs/routers/access/interfaces/nm/hardware/installation/guide/connhda.html

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