This paper begins with consideration on push technology in Java ORB environment, and investigates interoperability of event channels of the event service of CORBA, which should be technically addressed to build a true push service in a Java ORB environment. We present three different methods that enable one event channel to be connected with other event channels. Pros and cons of each method are described. All mentioned approaches have been implemented in Java. An experimental performance evaluation has been carried out and evaluation results are also given.