if you downloaded the jboss-3.xx-Tomcatxx distro an unse run.sh without any ohter parameters, the default server which contains a tomcat service is started.
the tomcat default port is 8080
if you try to go to yourhost:8080,
you should at least get a 404 error response from tomcat:
Apache Tomcat/4.0.1 - HTTP Status 404
The requested resource (/) is not available
that means tomcat is working well, but no context is configured.
you can also see that you have contacted tomcat by an entry in the access log in server/log
see the free docu for mor info.