title: TCP/IP ACK sender: Transport layer or the app?
body: <p>A newbie question: who exact send the ACK, the transport layer or the app? I have a COM-server with particle counters to send the data to my app. Sometimes I have a lost data. When I check the Wireshark protocol I see that the packets were sent from COM-Server but failed ACK from receiver. I think that ACK is missing because the my program has the error and can't edit the data properly. My colleague says that the interface (socket) simply gets no data and can't return ACK. Who is right?</p>