Chapter 5. Telephony Hardware Hacks
Hacks 59–71: Introduction
One of the reasons VoIP is such a positive evolutionary step for telecommunications is that it employs a highly distributed, software-centric design philosophy. It has the extensibility and programmability of the Internet, putting telephony power back into the hands of the users, not the phone companies. It is programmability—software—that makes IP telephony such a killer application.
Yet, critical parts of voice telecommunications are entirely in the domain of hardware. This chapter focuses mainly on hardware hacks: projects with a decidedly piquant, earthy flavor; projects that deal with analog telephone adapters (ATAs), phone line gateways, and “bat phones.” You won’t need much in the way of ‘l33t coding skills, but you’ll use some basic Perl. Have some Ethernet patch cables and Velcro handy. Oh, and it might help to have a bottle of XML on ice if the mood is right.
In this chapter, you’re going to be looking at VoIP and legacy telephony hardware—everything from state-of-the-art Internet Protocol (IP) phones to vintage rotary-dial candlestick phones—and how to get them working together. You might also pick up some handy tips for your cell phone, as well.
Record Calls the Old-Fashioned Way
Digital and IP phone handsets are analog inside, which means you can use a transducer microphone to record a phone call.
It’s fairly easy to record from a standard telephone using an inline recorder switch. These devices allow you to ...