, lesmemphis wrote

Hi, same data gets sent (flushed), but .End() will end the entire thread. So no code will be executed after I called .End()

Surely that's what you want? Once you have no more data to send to the client (i.e. after your final <CallBackResponse>Accepted</CallBackResponse>) you should call Response.End() which will immediately send the data you've written to Response and then get ready for the next incoming request.