Hi Friends, I am new to Ros an rosjava and tying to do something on my PC. I am not sure its correct or not. I am using rosjava on my Linux (ubuntu 10.4). Currently I am trying to run rosjava alone. and trying to use Talker and Listener example available in source. I am starting Ros core and talker and listener by following commands RosCore -- rosCore = new RosCore(11311); nodeRunner = NodeRunner.createDefault(); nodeRunner.run(rosCore, Lists.newArrayList("RosCore", "__master:= http://localhost:11311")); Talker nodeRunner.run(new Talker(),Lists.newArrayList("talker", "__ip:=127.0.0.1", "__master:=http://localhost:11311")); Listener nodeRunner.run(new Listener(),Lists.newArrayList("listener", "__ip:=127.0.0.1", "__master:=http://localhost:11311")); Publisher and subscriber are not able to communicate. AndI am trying to understand why.. I found that value of xmlRpcPort is 0 and not changed anywhere. Am I doing right thing by running rosjava alone? Is xmlRpcPort port need to set? whats is it for? I suppose it might be for remote communication with RcpCore (or MasterServer) in my case rosroot and ros package paths are empty...is that ok? Thanks and Regards Abhishek Verma