Using multiple applications on same port? (UDP) [Solved]

[tbscope]

Some tips:
1. Learn how peer to peer works
2. Learn about broadcasting messages
3. The most easy and ready made solution, connect 4 clients to a single server, let your server handle all the messages.

For solution 3, example:
Client 1 wants to send something to client 3, but they are not connected to each other. No problem, send a message to the server and tell the server to send it to client 3. etc. Just like a chat application would work. Every client is a client, not a server.

If you want every client to be a server too, see peer to peer. There's a bittorrent example in the Qt docs too.