What ports should be open in a firewall for mod_cluster?

Issue

• What ports should be open in a firewall that sits between Apache and JBoss connected using mod_cluster?
• I have configured mod_cluster with jboss eap6.1.1 an it doesn't work correctly. Why mod-cluster doesn't working fine?
• What are firewall requirements for mod_cluster?
• Require a definitive statement on the firewall rule requirements to allow mod_cluster to operate properly.