PSTN Gateway on Failover

When a phone becomes unregistered due to an outage and can’t reach the Skype for Business server for a specified time interval, the phone fails over to an alternate PSTN gateway server.

You can view the PSTN failover details in the Web Configuration Utility.

When you enable this feature, calls switch to the configured PSTN gateway in the event of an outage. However, if the phone fails over, only basic call-related functions and soft keys are available.

Make sure the value of call.enableOnNotRegistered and reg.x.srtp.simplifiedBestEffort parameter is set to 1.

Note: The failover feature does not work if you enable the hybrid line registration feature.

Ensure the Direct Inward Dialing number registered on the Skype for Business server and the number used for the PSTN gateway are same.