If you enable funneling, TS sets a public DNS record for your
node.tailnet.ts.net MagicDNS. That records points to public IP address of servers that TS controls. Similar to their DERP servers. Then they add the funnel server that handles the public side of the funnel to your tailnet. The server only offers a TCP connection that your node can reject or accept. You can set that up via the TS client. Admittedly, this part is a bit magical and I am waiting to see a follow up post on this.
But the reason of this post is not to talk about the funnel feature but about a nice visualization that TS has been using on their funnel related materials.
To create the funnel illusion, the world consists of four rectangle objects. Then we also have circles that are added every certain amount of time. Those circles start at the top of the plane/world so they fall as they would to in the real world. Eventually they hit the walls of the funnel (rectangles) or other circles.
When I saw the visualization I thought: what would happen if map actual funnel requests to the creation of those circles?
Mapping funnel requests to our physics world.
Now the data in the visualization is mapped to the actual funnel requests. Nice.