We are deploying web applications in java using tomcat on client machines across the country.

Once they are installed, we want to allow a remote access to these web applications through a central server, but we do not want our clients to have to open ports on their routers.

Is there a way to tunnel the http traffic in a way that the central server can access the web application that is behind the firewall ?

The central server has a static ip address and we have full control over it.

We don't need to access the filesystem, we only want to access the web application itself through a browser.