[Asterisk-Users] Fwd: [ISN] Voice Over IP Can Be Vulnerable To Hackers, Too

[Simon Dorfman]

On 5/14/04 9:02 PM, "tpanton at attglobal.net" <tpanton at attglobal.net> wrote:

> Folks seem to have forgotten that
> the original hackers were hacking
> "stable and secure" traditional PBXs
> with captain crunch whistles!
> 
> Mitnik ran wild through PBX's and mobille networks.
> 
> Let's work to set up secure VOIP, but
> don't let anyone kid you about the golden days when telephones were secure!
> 
> 
> (for extra points, why's the hacker mag called 2600?)

Extra points please:  because 2600Hertz is the frequency of the tone
required on the old phone system to get free calls.  There was a whistle
that came in a captain crunch box that happened to produce this exact
frequency.  Or something like that.  I'm too young to know this stuff first
hand... I suppose I could look it up...

Ah yes, google reveals this:
http://whatis.techtarget.com/definition/0,,sid9_gci211496,00.html
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 2600 is the frequency in hertz (cycles per second) that AT&T formerly put
as a steady signal on any long-distance telephone line that was not
currently in use. Prior to widespread use of out-of-band signaling, AT&T
used in-band signaling, meaning that signals about telephone connections
were transmitted on the same line as the voice conversations. Since no
signal at all on a line could indicate a pause in a voice conversation, some
other way was needed for the phone company to know when a line was free for
use. So AT&T put a steady 2600 hertz signal on all free lines. Knowing this,
certain people developed a way to use a whistle or other device to generate
a 2600 hertz tone on a line that was already in use, making it possible to
call anywhere in the world on the line without anyone being charged.
Cracking the phone system became a hobby for some in the mostly under-20 set
who came to be known as phreaks.

 In the 1960s, a breakfast cereal named Captain Crunch included a free
premium: a small whistle that generated a 2600 hertz signal. By dialing a
number and then blowing the whistle, you could fool the phone company into
thinking the line was not being used while, in fact, you were now free to
make a call to any destination in the world.

 Today, long-distance companies use Signaling System 7, which puts all
channel signals on a separate signaling channel, making it more difficult to
break into the phone system.
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Simon in New Orleans