Web服务器的UDP打孔？

Question

For my academic project, I am trying to achieve this. A web server node JS application listening on port 3000. So If you curl http://localhost:3000 you will get Hello World! . ( A simple web page.

Now I am running above webserver in my local machine. And my modem is behind NAT. Suppose If I port forward in the modem to myip:3000 then it is open to the world. But here is the biggest thing I am stuck - I don't want to use the modem for port forwarding, instead, I will use third party server for UDP Punch Hole.

Now my requirement is anyone from net should able to access my webserver at curl http://third-party-server-ip:3000 .

What I am trying is to write another client - which opens a connection to the third party server. Say it did a hole punching at port 41234 . That port is open. The third-party host can send something to that port.

Now anyone in the internet initiate this command curl http://third-party-ip:3000 to the third party host. So the third party returns the myip:udpPunchHolePort ie, myip:41234 .

anyone will again curl to myip:41234 it will be received by the node js UDP punch app, so it will redirect to localhost:3000 . Finally, the anyone will receive the response from localhost:3000 .

My two questions -

1. Is there any better way than the one I proposed here?
2. Is there any well-known node-js lib for this kind of stuff, I see, I can use UDP punch hole . Or I am thinking to write a Lib to do this in general - does this sounds like re-inventing the wheel?

Note - In this academic project, we are trying to learn how to make any local application open to the world without port forwarding in the modem.

We read on skype protocol analysis , that is also our inspiration.

Answer 1

No, that won't work.

1. HTTP runs over TCP, not UDP. Punching a UDP hole doesn't do you any good -- any TCP connection to the backend HTTP server will still fail.

2. HTTP redirects are not magic. If a user cannot access a specific host:port, redirecting them to a URL on that host:port will just make their browser time out when it requests that URL.

3. You cannot send a response from a different host:port from what the browser requested, because there is no TCP connection established with that endpoint.