Is there a tutorial on setting up a a multiplayer server on a *remote* server?

The Blueprint Networking tutorials on youtube are GREAT, major props to Epic on those, but I’m wanting to understand how I go about actually setting up a server to work over the internet. How do I tell it what ports to listen on, and all that? Does anyone know of some good material I could read about the process?

Basically, I want to allow my friend to help me playtest my little multiplayer game with me over the internet so I’ll want his client to be configured to connect to my server which I can run on my local machine or a virtual host.