A POC works using ordinary networking components and a common service called Internet Connection Sharing - or ICS for short.

ICS is available in multiple operating systems but for the sake of keeping things simple and easy to configure we will use Windows XP for this guide.

The purpose of ICS to allow you to share a single internet connection with 2 devices by connecting one device to the other and having one of them share the connection that it's receiving from another source.

This type of connection usually requires a special kind of CAT5 referred to as a "Cross-over cable" that allows PC-to-PC connections.
In this case, the connection is going PC-to-Router-to-PC so a standard CAT5 will work perfectly.

As mentioned, ICS requires an additional connection as to access the internet. In this example, we will be using a wireless adapter to connect to an existing wireless signal.

The POC will pick up the wireless signal using the wireless adapter and send the signal out through an ethernet port to a new router where you will be able to connect your devices (wired or wireless).

The easiest way to describe how it works is to show you, please refer to the 2 diagrams below.

Diagram A. Diagram A displays the setup of a typical home-network. The red line represents the path of the internet connection - starting at the Internet and passing through the router where it is sorted and sent to the corresponding device.

Diagram B. Diagram B displays the same setup while employing a POC on the same network. The red line represents the same path for the internet. The blue line represents the connection path after passing through the POC and creating a private sub-network. Since all the devices on the blue network pass through the POC it can regulate and end even encrypt data before it is sent to the public network.

Normally, an internet path would look like this :