Hack a VOIP Box Into a Telephone Intercom

Step 7 How it Works

Before we go further, let's talk about how this works. Normally, your VOIP box goes out over the internet and authenticates and communicates with a VOIP server. VOIP traffic normally uses TCP port 5060, with additional lines at 5061, 5062 etc... We're not going to use a VOIP server, though, so we don't need to authenticate to anything. Basically, we're going to have the adapter talk to itself on what is called the "loopback" address (127.0.0.1). We are going to configure each line with a port and a name. We are also going to enter a dialplan for each line that causes it to call the other line as soon as the phone goes off-hook.

Having the PAP2T plugged into a hub is only to keep the box thinking the network is available. It doesn't actually need to talk to anything else on the network.