If the gateway on the server to which the application is trying to connect is listening on a non-TLS port other than the default of 1025, applications can set the TDMSTPORT variable to the appropriate port. If the server is configured for TLS but is listening on a port other than the default TLS port of 443, applications can set the TDMSTTLSPORT variable to the appropriate port. This can be done instead of changing the entries in the services file.