From Door Tablet 8.2.0 you can configure the Door Tablet client to automatically switch to alternate servers in case the server they are currently connected is down for any reason. Switching servers takes place at the client end, as a result of connection errors.
Note: from version 8.4.5 you can request that a Door Tablet client uses a different server, remotely. This is done from the Tracking page.
To enable alternate servers, follow these steps: