Method, system and computer program to enable querying of resources in a certain context by definition of sip event package

摘要

Disclosed is a system and a method to provide event notification. The method operates an event server (20) with a subscriber unit (12). The method includes formulating a query; sending a subscription request message to the event server, the subscription request message comprising the query; responsive to a receipt of the subscription request message, parsing the query; and accepting the subscription request if the query is successfully parsed and understood, and if appropriate resource data is available to the event server to determine a result of the query.