We are developing an online game where the client will be a downloadable VC++ rich client and the server side game logic will be implemented in EJB with a servlet being the contact point for the client.
   The requirement is that, on occurance of some event, the server should send some data to all the clients currently connected. This 'send' operation should be initiated by the server itself ("server-initiated"), without waiting for the client to contact the server next time. (To achieve quick response/action)
   Considering the fact that the client and server are communicating over HTTP which is request/response based, how to achieve this 'server-initiated' communication without a client request?

Thanks
Rajit