corba client: Retries exceeded, couldn't reconnect vmcid: 0x0 minor code: 0 completed: No

Question

I have following code in corba client program:

Properties props = new java.util.Properties ();
props.setProperty ("org.omg.CORBA.ORBClass", "org.jacorb.orb.ORB");
props.setProperty ("org.omg.CORBA.ORBSingletonClass", "org.jacorb.orb.ORBSingleton");
final String ipStr = ip();
final String portStr = port();
String strNameService = "corbaloc::" + ipStr + ":" + portStr + "/NameService";
org.omg.CORBA.Object obj = orb.string_to_object(strNameService);
NamingContextExt ns = NamingContextExtHelper.narrow(obj);

This gives error:

Retries exceeded, couldn't reconnect to : vmcid: 0x0 minor code: 0 completed: No

What does error message mean? ip, port not correct?