This guide explains how to configure local PSTN survivability in an on-premise site or a remote branch office, so that when an Internet outage 

occurs, IP phone users can still make outbound calls through a local PSTN trunk via an AudioCodes gateway’s FXO ports.

The examples in this guide are based upon an AudioCodes MP-118 gateway with 4 FXS and 4 FXO ports.  Refer to the documentation for your gateway as 

needed (to find your AudioCodes user manual, searching for “LTRT-65417 MP-11x and MP-124 SIP User’s Manual Ver 6.6.pdf” in your web browser).

This guide comes with two files. (These two files can be found in the AltiGen Knowledge Base, along with this guide.) Store these files locally; you 

will need to upload them into the AudioCodes configuration tool during the procedures in this guide, on page 17.

• usa_tones_13_NoHold.ini

• usa_tones_13_NoHold.dat

IMPORTANT: AltiGen does not provide general configuration support for AudioCodes products. 

A support agreement with AudioCodes is required.

Update 7/10/2014: Proxy Redundancy Mode must be set to Homing.

This guide explains how to configure local PSTN survivability in an on-premise site or a remote branch office, so that when an Internet outage occurs, IP phone users can still make outbound calls through the local PSTN trunk via an AudioCodes gateway's FXO ports.

This guide comes with two files. Store these two files locally. You will need to upload these files during the procedures outlined in this guide.

IMPORTANT: AltiGen does not provide general configuration support for AudioCodes devices.

A support agreement with AudioCodes is required.