To access a service that only accepts requests at localhost:9090 at myserver, I can ssh tunnel from mypc to myserver:

ssh -L 9090:localhost:9090 -N myserver

Now, access to localhost:9090 at mypc would be forwarded to localhost:9090 at myserver.

More info on ssh tunnelling here.

Another example:

Say host-A can access host-B whereas mypc can only ssh to host-A but cannot access host-B. To access host-B from mypc:

ssh -N -p 22 -c 3des userid@host-A -L 9090/host-B/9090

Now, access to localhost:9090 at mypc would be forwarded to host-B:9090

jconsole ssh tunnelling

Now say one can normally jconsole via a service url like:

jconsole service:jmx:rmi://myhost:6160/jndi/rmi://myhost:6110/server

But if ports 6160 and 6110 are restricted, it would render jconsole almost useless. Here is how ssh tunnelling may come to rescue (if you are allowed to ssh to the host):

ssh -L 6160:localhost:6160 -N myhost
ssh -L 6110:localhost:6110 -N myhost
jconsole service:jmx:rmi://localhost:6160/jndi/rmi://localhost:6110/server

Oh, don't forget to start up the JVM with

    -Djava.rmi.server.hostname=localhost