Thursday, May 30, 2013

Down the telephonic rabbit hole

When I was younger, I longed to book passage to Oz or Narnia or any of the other magical worlds that seemed all-too accessible to my favorite literary characters.  My California beach town was sorely lacking in, say, mystical wardrobes or handy tornadoes.  Flying boys and large white rabbits were also in short supply, along with elfin spells, wizard staffs and fairy dust.  Why did all the enchanting stuff happen in books and not on my street?  It just wasn't fair!

Of course, like many kids, I wanted an escape from my daily life of school and chores and siblings. Not that I had much to complain about, but let's face it, battling evil and making friends with talking lions is a lot more fun than homework or even sleepovers.  I devoured stories about worlds my favorite authors created for me, and even learned to recognize and appreciate the most magical aspects of our physical reality: the solar system! Secret codes!  Venice!

Whose childhood phone looked like this?
Little did I know that throughout my childhood there was a gateway to a magical world sitting right on the desk in the kitchen.  Or, later, on my bedside table.  I didn't need a wardrobe or a wizard.  I just needed to pick up the phone.

If I had--and if I had been a little more techy or possessed of that tinkering spirit that has made so many young men rich in the past 30 years--I would have heard more than a dial tone on the end of the line.  I would have heard a siren song, beckoning me into a playground of musical tones, hidden operators and fantastical hardware.

Alas, I wasn't beckoned.  I, like you, just drummed my fingers on the desk waiting for the rotary dial to swing round or the long-distance call to go through.  But some people heard more than beeps, clicks and thunks. Like the lucky children who stepped into Narnia rather than touching the back of the wardrobe, some people found a way to enter that secret world and make themselves at home.  

They called themselves phone phreaks, and they are the subject of a wonderful new book by Phil Lapsley called Exploding the Phone: The Untold Story of the Teenagers and Outlaws Who Hacked Ma Bell.  In addition to delighting the reader with an endless cast of brilliant eccentrics and oddball geniuses, Lapsley gives us a close look at the Telephone System That Was, a truly fascinating alternate universe that existed under our very noses.

Until the mid-1980s, the telephone system was a giant analog web of wires that were physically connected to each other.  It was developed by AT&T, that government-sanctioned monopoly, and its research arm Bell Labs.  It costs billions of dollars to build, spanned the nation and connected us to the world.  Before transistors and microchips, before wireless networks and fiber optics, the geeks of that time still managed to connect millions of calls across thousands of miles every single day for more than 60 years.

A map of the long-distance phone system, 1961
When the phone phreaks figured out how they did it, the telephone network became their playground.  The key was learning how a call to your grandma got from your house to hers.  Remember, the connection was physical, in the sense that your wires talked to other wires who were connected to larger wires called trunk lines that connected cities to each other then tapered back down into smaller, local systems.  The phone phreaks figured out the secret language of the phones, the frequencies of the tones that allowed the telephone wires talk to each other.  They then figured out ways to mimic those tones to disconnect a call and then re-connect all over the system for free.  Some used high-tech frequency generators called blue boxes.  Others used musical instruments like recorders.  A few talented phreaks, many of them blind, just whistled to copy the tones.

The book is full of stories about how the phone phreaks discovered the mysteries of the system (a lot of trial and errors and sore dialing fingers) and what AT &T did to fight back.  But what fascinated me most was the sheer scale and wonder of the secret telephone world.  Bell Labs, in a rare fit of poetic extravagance, wrote that their switching stations "sang" to each other.  It wasn't too far from the truth.  Anyone who made a call from a landline in the 1980s knows what I'm talking about.  You dialed a number and then could hear similar (but not exact) tones playing down the wire.  Sometimes, you could hear what sounded like clicks or ker-chunks.  (If you made calls in the 1960s and 70s, you definitely heard these ker-chunks).  What was happening, as I learned from Lapsley, was that your number (in the form of tones) was being routed to a huge switching station the size of a city block called a crossbar switch.  There, the dialed digits actually changed the position on the switch and connected it other parts of the switching matrix (ker-chunk!)  This would serve to transfer your number to another trunk line. Your call might be routed through several of these huge switches before it got to its destination, necessarily making the connection fainter with each step.  Later, metal punch cards and light-detecting photo cells were used instead of moving switches.  Who remembers shouting into a long-distance line?  Well, now you know why. 

Just one small part of a crossbar switch

Imagine a telephone switching station the size of a city block!  Imagine bending this switching station to your will, speaking its language to tell it to connect you to Seattle or Duluth or Nova Scotia.  Imagine figuring out which tone disconnected the line but left it open (2,600 hertz, actually) and which numbers would get you to an internal operator who would know how to route the calls that big switches weren't smart enough to do.  Many phone phreaks were simply interested in exploring the system, using their knowledge to call unlisted phone company numbers like test lines.  Some tried to see how far they could get (Spain? India? Timbuktu?) or how complicated a routing they could generate based on what they knew.  Some discovered early "conference" lines on open circuits that those in the know could dial into.  Plenty of others (including Apple founders Steve Jobs and Steve Wozniak) profited by charging their friends a flat fee for a free long-distance call or by selling the blue boxes.

Regardless of their motives, the phone phreaks were explorers of a magical world that existed right alongside our daily life.  You may find little appeal in this wiry, auditory landscape, but reading about it in Lapsley's book makes it seem as vast and mysterious as Middle Earth--and populated with almost as many mysterious artifacts, astounding journeys and otherworldy characters.  

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