How to change the timeout for PSTN Calls

Not very often but from time to time we have problems during make overseas call or make calls to Mobile phones.
The Lync 2010 and 2013 has a value that is set to 10 seconds before it will terminate the calls.
We can change this value and this can be done by changeing this:
Configuring Parameters
Some of the above timeouts can be configured. The file which has the configurable parameters is 'OutboundRouting.exe.config”  Use caution when changing these values, as a rule of thumb try not to increase or decrease the value by more than 25% of its original value.

from OutboundRouting.exe.config
<configuration>
    <appSettings>
      <add key="FailOverTimeout" value="10000"/>
      <add key="MinGwWaitingTime" value="1"/>
      <add key="MaxGwWaitingTime" value="20"/>
      <add key="FailuresForGatewayDown" value="10"/>
      <add key="FailuresForGatewayLessPreferred" value="25"/>
      <!-- Valid values are between 5 and 600 -->
      <add key="HealthMonitoringInterval" value="300"/>
      <!-- Valid values are between 60 and 3600 -->
      <add key="GatewayStateReportingInterval" value="1800" />
  </appSettings>
</configuration>

The FailOverTimeout should be increased to the desired time limit.
The file is found under C:\Program Files\Microsoft\Lync Server 2010/2013\Server\Core

The valuse <add key="FailOverTimeout" value="10000"/> can be changed to 20000 on your frontend server(s) and you have to restart the Lync Frontend Service.

I have also seen issue with Audiocode Mediant 1000 gateways and when trying to make calls to Russia and other countries.