Are you asking which ports are opened, or how many? I can interpret your question either way. To find out which ports are open, use netstat, or if you are running Windows try TCPView.
I looked in the jmx-console at the MBeans under jboss.mq and jboss.mq.destinations and then closest I could fine was the ReceiversCount property for the specific topics and queue under jboss.mq.destinations (because each receiver has its own port). But I suspect that local MDB are in that count and I don't think that they use up ports.
You can dig further through those MBeans to see if there si something more pertinent.