I'm working on a project where a large number of clients will be connecting to a WCF web service. When they connect, the web service will sleep until an event occurs on another WCF service running on a different server. I want the other service to "wake up" the client service when the event occurs using another WCF service call on the backend, then notify the client that the event occurred. So my question is, what is the best way to search for the correct client instance based on a unique identifier so I can know which client thread to wake up? Is there a way to loop through all the open connections so I can find the one I'm looking for?