UDP problem

I tried to send data thru a UDP protocol using the WinSock control and well, it seems that the SendComplete and SendProgress events do not happen. Is there a way to be sure the other side received the data without wasting bandwidth for a check signal?

UDP is connectionless: it just sends the data, and crosses its fingers. you won't know if data gets there unless you have a check signal like you said. If you want to make sure stuff gets there, use TCP? (although a bit slower)