Annoying Dormitory Phones

by Chris Dickinson

I was around 23 years old and studying theology at a Swiss university.

The room at my dorm had a very simple phone, except for one peculiar feature: you needed to insert a special card if you wanted to make outbound calls.  You could get this card at the front desk for a monthly fee, and you would receive a bill at the end of every month for the calls made.  I was very low-tech in that period (flirting with the idea of entering a monastery), having neither a computer nor a cell phone of my own.  But I had a second phone, and it was because of this second phone that I made the following discovery.  When I inserted the card into the pre-installed phone to dial out, if I picked up my other phone to hear what was going on on the line, I could hear numbers being dialed at a rapid rate by the first phone.  This was what was granting the access to make outbound calls.

When I was a kid, we had an answering machine at my parents' house.

In order to call home from vacation and remotely navigate through the messages we had received, we had a little device that would generate the tones of a touch-tone keypad (this was useful in case the phone we were calling from was a rotary phone).  Playing with this little device as a kid had taught me that tone dial phones send out a dual-tone for each number pressed on the keypad.

So, back at my dorm, I decided to figure out what this number was that I heard being dialed when I inserted my phone card.  I did this by repeatedly inserting my phone card into the pre-installed phone and listening to the dual-tone melody on the other phone.

First, I would try to concentrate on only the one tone, and then on the other, writing down the entire melody for both tones (as I recall, it was a 13-digit number).  Combining the two melodies gave me the position on the keypad matrix of each number being dialed.  Within about 10 minutes, I had the code.  I punched it in manually and, lo-and-behold, I could make outgoing calls!

I soon figured out that the last seven digits or so were nothing else than a bunch of zeros followed by the two-digit number of my phone card.

This is what told the system whom to bill at the end of the month.  I realized that by using other peoples' card numbers I could very easily make phone calls on their bills.  But that wasn't the point.  Instead, I programmed the code into my phone's memory, along with the prefix for the phone company I wanted to use and the person I wanted to reach.  For example, instead of using that card and then dialing another 15 numbers to call my parents, I would just hit one of the memory combinations.  It was a big gain in convenience.

So far, so good.

But then, one summer, the phone company decided that we needed a new system.  They installed new phones, with LCD screens, that used RJ45 jacks and required us to use prepaid "taxcards;" cards originally created for our Swiss public phones (the LCD screen's main purpose was to let you know how fast your money was being swallowed up).  Calls were billed straight to the card and were expensive, costing about twice as much as before.  It no longer made any sense to use my pre-programmed codes to choose another provider, since I would be billed twice.

Put briefly, I hated the new system.

But, needless to say, I was curious how they had changed the technology for granting access for outbound calls.  I connected my second phone, pushed my newly acquired "taxcard" into the new phone, and heard that same familiar dialing sound.  Hmm... it was time for another tone analysis.

I worked out the new code, and it turned out it was the same code as before, only without the last seven digits for the old card we used to use!  They were now using the same basic code for everyone.  There was no longer any need to know who was calling out, since the phone took care of the billing itself.  Well, slowly but surely, it dawned upon me that I had not only figured out how to make calls without using a card, but that now, calling without a card actually meant calling for free!

Again, the point was not to make someone else pay for my calls, but convenience; in this case, the freedom to continue to choose through which phone company I wanted to make my calls.  In a certain sense, however, I was taking advantage of the situation, although it didn't occur to me at the time.  I was no longer being charged to make calls.

I was very happy with my new code until one day, while I was taking an early afternoon nap, I heard the janitor knock on my door.  I opened the door sleepily and found myself talking not only to the janitor, but to a representative of the company responsible for our phone system.  They wanted to take a look at my phone (which was unplugged and stored away somewhere).  This was where I had gotten sloppy.  I, far too quickly, decided that they must have figured out what I was doing.  Within a few minutes I was giving them a demonstration of how I could make free phone calls without the taxcard.  The janitor was impressed, the representative was not.  He told me that what I was doing was fraud and a criminal act.

In brief, it turned out that the new phones were more sophisticated than I thought possible.  They could silently communicate with the company, allowing the company to do nightly software upgrades to the phones.  Since I had unplugged the phone, the phone company thought there was a problem with it.  This was the reason for their visit.

The representative for that phone company sent a nasty letter to the dorm's board of directors (the dorm was owned by the Catholic church), who in turn was asked to send a letter of complaint to my superiors in the church hierarchy (those responsible for getting me a job in the church later on, so I thought at the time).

What ensued were a few talks with my superiors and the director of the dorm, all of whom had no idea what I was talking about when I tried to explain to them that I had discovered the code long before I could use it to "make calls for free," that I was not actually making free calls, etc., and they expressed their surprise at my criminal activities.

It turned out not to be a big deal, but I was unhappy about the letter nonetheless.

The story had one more interesting turn, however.

About a year later, the director of the dorm, who knew me only because of this issue, came to me with the following proposal.  The nearly 100 students at the dorm all hated the new system.  It wasn't being used, and it was time to find a better solution.

Who did he ask to find this solution?  Me!

I was to get paid for this research, as well.  I proudly accepted the offer and, together with a computer-savvy friend, worked out a plan for combined phone and Internet access for all rooms (with another company, of course).

Meanwhile, I graduated but decided not to work as a minister after all.

Instead, I'm getting a degree in IT, which seems to suit me a lot better.