7.2. "port"

The "port" SvcParamKey defines the TCP or UDP port that should be used to reach this alternative endpoint. If this key is not present, clients SHALL use the authority endpoint's port number.

The presentation value of the SvcParamValue is a single decimal integer between 0 and 65535 in ASCII. Any other value (e.g., an empty value) is a syntax error. To enable simpler parsing, this SvcParamValue MUST NOT contain escape sequences.

The wire format of the SvcParamValue is the corresponding 2-octet numeric value in network byte order.

If a port-restricting firewall is in place between some client and the service endpoint, changing the port number might cause that client to lose access to the service, so operators should exercise caution when using this SvcParamKey to specify a non-default port.