The above documents list the default ports and protocols; so at a bare minimum you'll need port 80 open. If you want your clients to access your NS through a firewall/DMZ, I would suggest defining a non-standard port under 1024 for the Agents to use (at least for communication with the NS; Task Server functionality may be a different animal)! I had a similar question on another thread that may help you (see my first comment, about halfway down the page).