Accessing Tomcat server in DMZ

I'm having difficulty getting App. Manager to monitor some of our Tomcat servers that reside in the DMZ. The App. Manager server is inside the DMZ, and I'm configuring it to monitor a series of servers all located in the DMZ with manager running on port 7001. I can connect to the Tomcat manager using the same address/port from my own machine, but the App. Manager server fails.

As far as I know all communication from inside the network TO the DMZ is unrestricted. Traffic from machines in the DMZ back into the network is however limited. Are there any other ports which need to be allowed back into the network for App. Manager to communicate with a Tomcat server?

Thanks,

Tom