Currently, a TLS transport for a specific domain can only listen on one port.
If you attempt to configure two ports for the same TLS domain (e.g. both 443 and 5061 on the same IP address) then this error is logged at startup:
ErrLog(<< "Failed to add secure transport, transport with similar
properties already exists: " << tuple);
If multiple transports are available on different ports for the same TLS domain, then only one of them should be used for all outgoing connections and it should be deterministic.