CDAP components communicate over your network with HBase, HDFS, and YARN. For the best performance, CDAP components should be located on the same LAN, ideally running at 1 Gbps or faster. A good rule of thumb is to treat CDAP components as you would Hadoop datanodes.
See the section below (CDAP and Firewalls) for information on configuring CDAP with a firewall and the listening ports that are used.