Thanks, I'm aware of Comet. Not exactly what I meant, in Comet the connection stays open after being initiated by the client. I'm looking for something where

Thanks, I'm aware of Comet. Not exactly what I meant, in Comet the connection stays open after being initiated by the client. I'm looking for something where the interaction is first client-to-server, then client registers a "callback" address and port that it will listen to. This would be followed by a server-to-client call where the server will send updates/events to client as they happen, the client then decides what to do with those events. I want to avoid a persistent connection, and either the "heartbeat" client requests or other forms of polling by the client. The interaction that I'm looking for is more akin to a P2P sort of model.