When we call a remote web services in an asynchronous way, we could return the invocation immediately and later we could either call Endxxx or our suppied callback will be invoked when the asynchronous call result is ready.
My question is, how will the result be delivered to client?
- Does the proxy on client side opens a port and listen to the return SOAP message containing the result?
- Does the client use keep alive technique and keeps the Http connection open/live from the beginning (when we call BeginXXX to invoke the web services) to the end (when the result is ready) -- if implemented in this way, there is no need for the client to open a port to listen?
- Or implemented in some other ways?
thanks in advance,