title: multiple connections on one port
body: <p>I run multiple bonjour client using pidgin, A, B, and C.<br>
  when B and C talk  to A , I find A uses the same port (with wireshark I can see the packets) for MDNS and communication,<br>
  but B and C, each has two different ports one for MDNS ,one for socket connection.<br>
  how does A work, why it can work with only one port? how can one port provides multiple connections? <br>
  Attention: if it is multithread ,then when it accepts a connection it will create a new socket with another free port, but I saw the packets from wireshark, client A did just use the same port for communication and MDNS. <br></p>