Our desire for the event notification service to be general purpose also compli- cates the routing problem for the service. In particular, we assume that objects of interest have no knowledge of interested parties. Therefore, event notifica- tions cannot be addressed and routed in the same, relatively simple manner as, for example, an electronic mail message. Moreover, we cannot assume any particular locality of objects of interest and interested parties, which is a fact that bears a strong relationship to the server topology issue. At best we can only try to take advantage of any locality or structure in the message traffic as it demonstrate below that.
