The syntax of the MQTT transporting protocol URL used in the Address parameter defined in 6.2.6.3 has the following form:

mqtts://<domain name>[:<port>][/<path>]

The default port is 8883.

The syntax for an MQTT URL over Web Sockets has the following form:

wss://<domain name>[:<port>][/<path>]

The default port is 443.