Relay Server URL Suffix – the URL
                                suffix to be used when the device client is connecting through Relay
                                Server. The suffix you set depends on whether Relay Server is
                                installed on IIS or Apache. For IIS, this path is relative.
                                Acceptable values include:- For IIS – use/ias_relay_server/client/rs_client.dll.
                                    
 
- For Apache – use /cli/iasrelayserver. 
 
Note: The value used in the client application connection
                for the URL suffix must match what the administrator configures in the URL suffix.
                Otherwise, the connection fails. Use the Diagnostic Tool command line utility to
                test these values. See  Diagnostic Tool Command Line Utility
                    (diagtool.exe) Reference  in
                    System Administration.