Conceptually my problem looks like this: I got one web site on VPS with one dedicated IP (Ubuntu Linux). This site accepts files from user, which are to be processed in some way on other computer. So I placed a script on my site server: it prepares files (collects metadata and archive the files) and can send it to some IP via http protocol (curl utlilte).
On the other end of the connection my other program accepts incoming requests (Win7 + C# + HttpListener) and process income files. The result is sent to S3 storage.
What is the easiest way to establish connection between 2 computers so they could access the internet each through their own connection and to be accessible for each other through their IP?
I'm a newbie in networking so I suppose that there's no "easiest way"