: Hello everyone,
: 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,
When you call a web service asynchronously the TCP socket remains open until the request is completed. It is asynchronous because the socket waits in a background thread for the response while the rest of your program continues as normal. Once the response is received the background thread calls the callback method.
There is no reason for you to open additional ports or look for another TCP connection.