@xpcontact This depends on a couple things. Are you running Apache or nginx on port 80 on that host right now? If the answer is no, just change the port to 80 in the config.json and restart app.js.
If the answer if yes, you need to proxy/reverse proxy the connection through apache or nginx.
A couple things I ran into with these configurations.
Apache needs to be on 2.4.x branch to support websockets via proxy.
Running nginx, you need to be on the 1.4 branch of code to support websockets.
There is a guide to this in the nodebbwiki for use with nginx, and I posted my config in this thread http://community.nodebb.org/topic/761/takes-a-few-seconds-for-it-to-show-users-and-that-i-m-logged-in for how to use it in an apache environment.