PHILTEL

To power the telephone network that drives the payphones, we are making use of commodity hardware (especially used/discarded and low-power-consumption hardware) and open-source software where available. The workhorse of our network is an Asterisk-based Public Branch eXchange (PBX) running on a virtual private server (VPS) on the Internet. Asterisk acts a bit like a bridge between the Public Switched Telephone Network (PSTN) and our collection of payphones; we can facilitate connections between the payphones and the outside world seamlessly. To connect to the PSTN, we get service through a Voice over Internet Protocol (VoIP) provider (think of them like an Internet Service Provider but for telephony). However, Asterisk is much more powerful than a simple traffic controller, and it lets us create our own services or connections to private telephone networks that any caller can access!... Building an amateur payphone network in Philadelphia.