title: Losing data with UDP over WiFi when multicasting
body: <p>I'm currently working a network protocol which includes a client-to-client system with auto-discovering of clients on the current local network.</p>
  
  <p>Right now, I'm periodically broadsting over <code>255.255.255.255</code> and if a client doesn't emit for 30 seconds I consider it dead (then offline). The goal is to keep an up-to-date list of clients runing. It's working well using UDP, but UDP does not ensure that the packets have been sucessfully delivered. So when it comes to the WiFi parts of the network, I sometimes have "false postivives" of dead clients. Currently I've reduced the time between 2 broadcasts to solve the issue (still not working well), but I don't find this clean.</p>
  
  <p>Is there anything I can do to keep a list of "online" clients without this risk of "false positives" ?</p>