IIoSvc Node1 IIoSvc + ~IIoSvc() + open() + close() + has_fd() + fd() + fname() + mode() + IoTypeName() + IoTypeFromName() + interfaceID() Node3 IoSvc - m_fds - m_last_fd + IoSvc() + ~IoSvc() + initialize() + finalize() + queryInterface() + has_fd() + fd() + fname() + mode() + open() + close() + interfaceID() - IoSvc() Node1->Node3 Node2 IService Node2->Node1