Is it possible to make a browser client for this?

[creationix]

I'm thinking it would be really cool if a browser (with assistance from some known servers for the discovery phase) could make peer connections to servers running behind a nat.

It would obviously need to be websocket or HTTP protocol over hole punched TCP so that the browser could make the actual connection without the help of a proxy.

Is this feasible and what's the minimal server setup needed to make it happen?

What if I wanted to write a browser extension instead of deploying servers? Would that work as well?