title: UDP socket. How to determine if data is sent to wire?
body: <p>I'm using UDP socket. The server application sends to the client information about how much time the client should transmit data to server. Then, the client begins transmission during this time by sending specific packets.</p>
  
  <p>So I need a way to determine if data were sent to wire after <i>Sendto()</i> to find out how much time the client is sending in real. Does it exist?</p>
  
  <p>OS: Windows 7</p>
  
  <p>I tried to use perfomance counters (<i>Network interface \ Output Queue Length</i>) but it is always 0;</p>
  
  <p>One more way I know is to set SO_SNDBUF ( <i>setsockopt()</i> )to the size of packet to send. So <i>sendto()</i> blocks until the send socket buffer is full (previous packet isn't sent to network interfrace buffer). But it seems that it doesn't work, just because it works only with socket buffer not network interface buffer.</p>
  
  <p>I'm also interested in solutions for Linux.</p>