How does a server know a client is trying to conne (wodVPN)
I understand how the firewall hole punching works via the Search method. For it to work they must Search for each at the same time via a mediator, they then get each others IP address and port, then connect to each other at roughly the same time.
However, this begs the question: if you are acting as a server (behind a firewall), and anyone can connect (with the correct password), how do you know a client is trying to connect to you so that you can Search for them via the mediator at the same time? The server not only needs to know if a client is trying to connect, but it also needs to know the ID of the client.
The only way I can think of for the server to know if someone is trying to connect to them (and who they are) is to use a web service (e.g. a PHP script on a web site) and ask it every few seconds Is anyone trying to contact me, and if so, who are they? . This doesn't seem like an ideal situation, especially if you have tens of thousands of servers.
Is there a better way? Or am I going about this the wrong way?
Thanks