[373] in Privacy_Forum
[ PRIVACY Forum ] Do It Yourself Slydial -- Even Dumber Than I
daemon@ATHENA.MIT.EDU (privacy@vortex.com)
Sun Aug 3 04:01:45 2008
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Date: Sun, 03 Aug 2008 00:42:29 -0700
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Do It Yourself Slydial -- Even Dumber Than I Thought!
http://lauren.vortex.com/archive/000411.html
Greetings. When I wrote last night about the stupidity of Slydial's
patent application and proposed a methodology for how their service
functioned ( http://lauren.vortex.com/archive/000410.html ), it
turns out that I was missing one fascinating piece of information.
It appears that I actually gave the Slydial folks *too much*
credit. I've now learned that Slydial does not reliably function
for all destination numbers without either leaving a "missed call"
indication or actually ringing the destination phone once or twice.
As "Emily Litella" used to say, "Oh, that's very different!"
Now we can see the light and can duplicate this functionality with
ease. The extremely likely "secret" mechanism: Multiple phone calls!
In fact, earlier today, Bob Frankston had joked with me about the
possibility of using two calls to get one to voicemail, but of
course we both knew this wouldn't work if there was also the
requirement of no ring or other indication to the destination phone
of the call, other than a voicemail alert. With this requirement
dropped, the procedure becomes clear.
You make two calls (on two lines) to the same destination number at
essentially the same time from a single origin point. We'll assume
that the first call initiated will complete first -- a very good bet
in this circumstance. You probably want to stagger the calls very
slightly -- a second or two should be fine. The stagger avoids
problems that can occur in same cases when two calls hit the same
single line service at the same instant, and also helps to assure
that you know which of the calls will go to voicemail and which you
want to abandon.
If you're willing to chance ringing the destination phone, just wait
until you hear the start of a ring then drop that call. The second
call should bounce directly to voicemail. If you want a shot at
avoiding the ring, wait a couple of seconds for the connection to
likely complete, then drop the first call. Depending on the ring
sequencing of the destination carrier/number, a ring can probably be
avoided in many cases. There are some other obvious tricks that
could make ring avoidance even more certain.
This technique duplicates the Slydial symptoms that I've now seen
reported. If you don't drop the first call fast enough, you'll
trigger ringing. If you drop during or before the ringing (but
after the call completes to the switch) you're likely to trigger a
"missed call" indication much of the time. In both cases you may
also trigger a caller-ID display (if not blocked by the calling
number, of course).
But what about call waiting? We don't care about call waiting!
First, if no current call is in progress to the destination phone,
call waiting will normally not be triggered. Call #1 is the set up
and enters the connect/ringing sequence, and call #2 bounces
straight to voicemail. And if a "real" call is in progress, our set
up call #1 will simply trigger a call wait beep (but by the time the
person called can get to it that set up call will be dropped) and
our call #2 will bounce to voicemail -- exactly what we want to
happen.
In testing with a couple of landlines and my own cell phone earlier
today, I was able to make this work 100% of the time after just a
few minutes of "tuning" my technique.
So there you go. You can do it yourself. But, uh, keep in mind
that some folks might consider those initial abandoned calls
(especially if they ring) to be harassment. You don't need Slydial
to pull off this stunt, though obviously they make it easier since
you don't have to use a couple of your own lines.
And if any of this tomfoolery rates a patent, then we might as well
all pack it in -- the lunatics will have taken absolute and total
control.
"Your call cannot be completed as dialed ..."
--Lauren--
Lauren Weinstein
lauren@vortex.com or lauren@pfir.org
Tel: +1 (818) 225-2800
http://www.pfir.org/lauren
Co-Founder, PFIR
- People For Internet Responsibility - http://www.pfir.org
Co-Founder, NNSquad
- Network Neutrality Squad - http://www.nnsquad.org
Founder, PRIVACY Forum - http://www.vortex.com
Member, ACM Committee on Computers and Public Policy
Lauren's Blog: http://lauren.vortex.com
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