ENHANCED PRESENCE ROUTING AND ROSTER FIDELITY BY PROACTIVE CRASHED ENDPOINT DETECTION

摘要

Endpoint crashes in a real time communication system are detected by a home server providing presence and other services to the endpoint upon receipt of an error message from an access server between the endpoint and the home server. The home server uses a cookie inserted into a dialog between itself and the endpoint identifying the endpoint, a session state created by the access server identifying the endpoint, or a transaction state maintained by the home server to look up the endpoint associated with the error message. Race conditions occurring when an endpoint crashes and recovers rapidly can be avoided employing a timestamp or sequence number incremented for each new endpoint registration and comparing a current timestamp or sequence number to the stored one before updating records at the home server. By notifying other subscribers about crashed endpoints, routing fidelity is enhanced.