hpr-knowledge-base/hpr_transcripts/hpr0419.txt

Episode: 419
Title: HPR0419: ConfCon09 - Project MF
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr0419/hpr0419.mp3
Transcribed: 2025-10-07 20:12:45

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MUSIC
Good afternoon, this is Don Frola, and my free handle I've been using as of late is the
very unoriginal DF-99, which are just my initials with a convenient two digits.
So you see me on bin rev, which I tend to hang out on, that's generally what I'm known
as if you happen to spot some postings regarding project MF. I've been pretty much a one-trick
pony with this project MF deal, and it's sort of my contribution to the old school hacking
community. So I'm very, very pleased to be here this afternoon to be able to talk about
my implementation of project MF, which I've had publicly available for about three years
now, pretty much 24-7 with. It's really almost no downtime, and it gets fairly heavy usage,
I'd say, I get about 15, 20 calls a day on it with people freaking around. So very gratifying
to have done that, and make it available to the freaking community, and I'm very grateful
for the people who did some of the pioneering work to make it all possible. So I'd like to,
hopefully I won't run over, so I'm going to ask the moderator to try to keep me honest,
you're, I've got quite a bit, I'd like to accomplish it if I'm encroaching on time,
please let me know, and I'll just, you know, end the discussion as quickly as possible.
Just to give a little personal background about myself, I'm a phone freak from the classic
phone freak days, I guess, back in the late 60s and early 70s, so I'm probably a bit old
in the most people here. My involvement with phone freaking started out in 1968 when I found
an old Princess telephone in a junk shop, and somebody told me that I could wire it up
to my home phone even though the front of the telephone told me I wasn't supposed to
do that. I brought it home and kind of squinted at that little black box on the basement and
figured out that you just needed two wires to hook it up. And I had a knock on the door
from the phone company who told me to turn it off, and then another guy who was in the
note told me, well, you got to disconnect that bell, so the phone company won't know
it's there. So that really peaked my interest that there were things that could be done
to manipulate the phone company's knowledge of what was being done with their lines and
equipment. So that sort of got started a very latent kind of interest in the telephone
system that really didn't get re-awakened until a lot later when I was in college as a
liberal arts major. And I was down in the student union and I saw a guy with a little box
walk up to a phone and this box started playing kind of funny tones. So I went over and
asked him what it was and he explained it's a blue box and he proceeded to make some
calls to Vietnam to his brother who happened to be over there at the time, which I found
absolutely amazing. So I asked him about it but he didn't give me much technical information
but again, I kind of planted a seed and then in 1971 when the S-square article came
out that I'm sure most of all of you are familiar with on the phone freak underground
and blue boxing in particular, it just really got me really excited. So I went on to the
school library and read basically every copy of the bell system technical journal they
had there. And about a week later, I changed my major to engineering and so I view phone
freaking as being responsible for a 30-year career on telecommunications. So I feel I
owe a lot to the community for that because it's paid my family's expenses for the last
30 years and always have been interested in trying to recapture that thrill back in the
70s of using the blue box and making calls. So I was quite active at the time. I built
my first box in 1971 out of a couple of 555 timers and back in the 80s when I got a little
more knowledgeable, I constructed a 68-HC-705 microprocessor based unit that was kind of inspired
by the old Hectic Demon Diler blue box circuit which I consider the epitome of the art
at least for the time. But back on Project MF, kind of fast forward to the present, it came to my
attention that a well-known phone freak Mark Abeen, also known as Fiber Optic, was giving a
presentation at the HOF6 conference in the summer of 2006 and the subject of his talk was Project
MF. And what Mark had done, which I found quite amazing, is to take the asterisk free PBX software
system that I'm sure all of us are familiar with on the conference. And apply a series of patches
that allowed the lines to respond to the old 2600 heard supervisory tones and also respond
to the multi-frequency tones for dialing. And basically it allowed a totally private system,
a person the ability to blue box calls. And Mark demoed this system and his modifications at HOF6.
We also kicked off the www.projectMF.com discussion board. And that's still up there although
Mark has kind of dropped below the radar the last couple of years and it doesn't get a lot of
activity. But he put that up to spark some technical discussion about how to implement his patches.
Surprisingly because of the complexity of applying the patches and getting the system up and running,
very few people actually have accomplished it to my knowledge. And to my awareness nobody has
actually put up a publicly accessible system. So my goal was to try to make this reliable,
first of all reliable, simple to use to simulate as much as possible the sound of the old network
and to give a person dialing with a blue box or with a blue box program. The experience of
actually blue boxing as it would have been back in the well even in the 60s but through the 70s
and throughout the 80s and maybe a little bit in the early 90s so there would probably be some
argument about whether blue boxing is still possible today. So that was sort of my design goals for
it. So what I did is I took Mark's original set of patches and I doctored them up a bit and
wrote some additional code to try to make it sound a little more realistic. I added a fairly
authentic sounding Wink tone to it. I increased the reliability of the MF detectors so that
was in place and caused through they had a pretty good chance of success using almost anything that
could generate the required tones. So I do have this, what I also did last year is set up a
website dedicated to the project. It's similar to Mark's URL. It's www.projectmf.org for RG. So it's
again almost very similar and I put a lot of details about the project MF system and about
construction details for a blue box which I'll talk about a little bit later in my presentation.
So a person can dial in on the DID number which is 630-485-2995 and they will get connected
into a voice explanation of the system and how it works and how to access it and it drops you
onto a trunk and allows you to blue box if you've got a blue box or a program that's capable of
producing the correct tones. Now on my website www.projectmf.org I do have a software
Windows software blue box that allows you to use the number keypad on a full size keyboard almost
as a real hardware blue box. So for those who don't want to get into constructing it it's a simple
download and it's simple install and that provides a pretty convenient manual blue box to
interface into the system. I also have set up the capability for people to connect to the system
directly through SIP. There's details of this again on the website so I won't get into them now
but if you have a SIP or a soft phone you can directly connect over the internet without
going through the PSTM. There's also IAX2 which is the asterisk voiceover IP protocol. If you
have an asterisk server you just have to that with the dial plan to access my box directly without
going over the PSTM and again there are instructions for doing that if you've got a server and want
to create a direct link for full and around with it. All these systems work I've tested thoroughly
and work really well with the system. There's also another cool gateway that I have and I
connecting into a system called CNET or the Collector's Network and this is a very interesting
group of people who collect electro-mechanical historical switches in their basements and these
people would get the stuff that these old switches that were basically being sold for scrap and
reassemble them, clean them up and actually get them working in their basement. They discovered
it was kind of boring because basically they had this huge power-hungry intercom system that
really couldn't talk to the rest of the world. So a couple of very smart people discovered how to
use asterisk to tandem or to interconnect these switches using this over IP and they've come up with
a very sophisticated set of DNS lookups and so forth that make it possible to have a private
network that lets you dial in directly into these historical old electro-mechanical switches.
Adding my system into this network allows you to actually blue box into a real old step or
cross bar five or any of a number of other historic switches that are up on this. And that is a
real kick to be able to blue box and get into some of these old systems and actually live in
these five big stones. So there's quite a bit of connectivity into my project and that system.
The hardware system I'm using itself is actually quite simple. It's an old
white thin client diskless workstation that I've modified to use a compact flash to boot
Debbie and asterisk and I'm running asterisk 1.2 on it. And I've got asterisk patched with the
project MF patches that make off all the tone detection possible. Now the cool and what I think
is cool thing about it is to make a call using a blue box you need a set of trunks that are
responsive to the 2600 Hertz tone and the multi-frequency tones. Now the way I'm doing that on asterisk
is I've got two extra ethernet cards installed in addition to the one that provides network access
and I have a crossover cable connecting the two nick ports together back to back. So they're
looped back to each other. Asterisk has a little known capability of putting a T1 interface up
over a ethernet interface. So what I've done is I've created two trunk groups of 24 channels each
the size of a standard T1 interface. Those are interconnected so I have one outgoing trunk
group of 24 SF MF trunks that go and loop back into the switch. So I'm running a tandem that
essentially is both the originating and the terminating side at the same time. Now when a call is
made using project MF it actually loops out one of the actually selects one of the 24 trunks.
And the fact you've got 24 make a lot of kind of cool things possible because you can
do trunk stacking like you'll hear on the Evan doorbell phone trips tapes. You can pretty much
simulate exactly what he demonstrates there by having these additional trunks available and it
is a multi-user system so you can have many many people up using the system at the same time.
So that's basically the hardware platform that I'm using and it's with the compact flash
rather than hard disk interface. It's exceptionally reliable and very low power. I've got
battery backup on it and a whole bunch of other things to kind of enhance the reliability.
I'm going to stop any questions at this point or before I kind of dive into some of the basics of
how it works. I don't see one thing I'd like to just say is I'd just like to remind everybody
that please mute their phones because you know project MF is very you know it can get interrupted
very easily so please mute your phones and I'll let you continue to talk. Okay thank you yeah
I'll let you know and that's strictly necessary when I start doing the demo that will be
kind of requirement to have a quiet life. Although from what I can hear I don't think we're
going to have any problems with them. So let me talk a little bit about blue box
box basics and I apologize to people if this is very well-known stuff and I'm it's kind of
necessary to understand what's going on. So so basically the way a blue box works is that it
basically simulates the supervision and the digit addressing functions of a telephone system
and the easiest way to understand it is to think about what happens when you've got your telephone.
When you pick up the phone what happens is a switch closes in the telephone instrument
which completes a circuit into an automated switch which returns a dial tone to you. That dial
tone is your signal to start pressing the buttons sending DTM up tones into the switch which
then routes your call. That is the local level of telephone access that we all have the local loop.
Now there's a second level of access. The first level is the wire loop that connects your phone
into your neighborhood switch but the second level is the trunk level access and trunk level
trunks are basically telephone lines special purpose lines that interconnect switches rather than
connecting a telephone instrument into the switch your local switch and those trunk circuits that
interconnect switches are just like your in some ways just like your local telephone line. They
require supervision they require an on-hook and off-hook detection or signal to be sent and they
also require digits to be sent or some form of telephone number addressing so that digits can
be sent from the originating side of the trunk back to the terminating side for routing a call.
Now in the case of your local instrument you're using DC or you're using basically a DC signaling path
but on trunk connections where the distance between the switches that are being interconnected
is quite large it's necessary to sometimes put the connection over transformers or amplifiers and
what an amplifier does when you insert it into a phone line is it breaks that DC connection you
no longer can signal using an opener a closed switch passing current through a wire so the telephone
engineers realizing this problem came up with the using the idea of using a series of tones which
will pass through an amplifier to anyone who's hooked up a stereo knows it'll also pass through
a transformer or any number of different carrier systems that the telephone company might use on
their trunk circuits. So the system that the phone company came up with back in the late 40s
is to use a 2600 Hertz tone as a supervisory signal so for example when your phone your local
phone is on the hook no current is flowing that's an on hook state that is indicated on a trunk
level by the presence of a 2600 Hertz tone on the trunk that indicates that the trunk is idle
and in use when that tone is removed that's a signal to the other side the receiving side of
the trunk circuit that the person's picked up the phone or picked up the trunk in this case it's
the switch grabbing or seizing the trunk going off hook instead of returning a dial tone the
far end of the trunk will send what is called a wink it's a momentary on hook indication so
what it'll do is when it removes the 2600 Hertz to indicate that the line isn't used but then
very briefly the far side will send a little cheap of 2600 and that tells the near side oh it's
like a dial tone it says okay I can go ahead and send my digits and the digits being used in the
case of the trunk circuit are multi-frequency or MF digits which sound in some way similar to
the your normal touch tone pad but actually use a different set of frequencies to transmit the data
so that's sort of the basics of how it works now I thought I would do just a very brief
demonstration of what the tone sound like the 2600 tone that indicates an on hook state sounds like this
early famous tone so so when the trunk isn't doing anything that tone is just playing
when the tone disappears that means the trunk is in use now after the wink back is sent the
the trunk will then send the digits of the call to be dialed now just for comparison let me play
what all the touch the standard touch tones sound like I mean you of course heard these but I'll
play them anyway just to get them in your head hopefully did asterisk mute those I'm curious
did they go a lot of us using like five years and stopped it through it should be fine okay so
hopefully you heard the tones now the MF tones sound a bit more musical and to my mind more
pleasant but let me play the same set of 12 MF tones and those are your multi frequency tones
now before multi frequency was used there was still another method that was used to simulate
telephone dialing using a dial using tones so instead of the dial opening and closing a switch
interrupted DC current running through a phone instrument at the trunk level to get around that
restriction of not being able to pass DC that I talked about before they actually sent pulses of
the 2600 hertz tone that would that would correspond to the DC pulses on a telephone switch on a
telephone dial on a local subscriber loop and in fact when you were connected into one of these
trunks using your telephone dial your dial was actually generating bursts of 2600 that
corresponded to the digit of this dial so for example a zero would sound like this
I'll do that again and that's the exact rate of a telephone dial but using 2600 hertz tone so
let me dial a number just to show you what it would sound like
so that was a full ten-duty did your phone number now that's not as efficient as the MF tones
so that that system was quickly it was quickly replaced by MF now the famous phone for
Joe and Grecia also known as joy bubbles could actually whistle those tone bursts that I just played
first I thought Joe when I first heard about Joe I some of the news articles that were written
about him were quite accurate about what he could do they were saying that he could whistle MF
tones and I actually talked to Joe about that he said that was even beyond me I couldn't whistle
two tones at the same time but what he could do is he could whistle in the crack cadence and hit
the frequency accurately enough that he could actually dial those those pulses quite accurately
and place free phone calls using it now I as I mentioned I had constructed two different
blue box circuits one was a fairly complicated circuit based on an old Motorola microprocessor
what I wanted to do as part of my project MF system is to sort of complete the design by making
inexpensive blue box available to people who wanted to play with it so I mine ahead and I designed
a a blue box that was based on a micro chip pick microprocessor it's a little 8 pin pick
very simple circuit that interfaces a keypad or a set of switches to this little pick and
generates all of the tones needed to to make a basic blue box basically 2600 and the multi-frequency
tones a person who collaborated me with this was a gentleman named Phil Lapsley who runs a website
called the history of phone freaking dot com and he also spoke at the last hope last year and gave
a presentation on the history of phone freaking well Phil and I got together and he took this
design that I put together and we produced a series of very professional printed circuit boards
had those produced tested them out and debugged them and the Phil passed about 200 of those out at
the last hope in 2008 so some of you may have actually picked one of those up there were a
designed to fit into a little radio shack enclosure and then I I had instructions and the parts
list up on my site to complete it I actually do sell the PCBs and the pre program picks for
anybody who's interested in in building one of the designs but it makes a very nice little
contact blue box very tiny very much like the square article blue box so again those were put
out at the last hope and there are plans and a contact for asking and querying about sales of
those on projectmf.org so I'll get a little plug in for that some of the features on the box
that are kind of cool is that it it's not like the old blue boxes it will actually play both
and dtmf tones plus the 2600 it has 30 it has I'm sorry 12 32 digit memories on it so you can
store digit sequences and play those back into the phone for experimentation so I've I've
actually sold a few hundred of these so there's a lot of latent phone freaks or x phone freaks
out there who just for nostalgia's sake or maybe the play with project mf have been quite
interested in that project so what I thought I do now and if there's no questions about what I
talked about is actually dial into the project mf server now I'll try to pre-party and in here
and a demo kind of how the system works and talk to anybody some of the codes I've pulled in
to do it and how that works now I am hearing some road noise or background noise on there so at
this point in the presentation I would ask everybody who has the capability to try to mute their
phone the mf detectors are quite sensitive and it'll fill and chirp at any extraneous noises
as mf digits so it would be it would be great if people could meet the connections uh any questions
at this point uh about that presentation that part of the presentation anyway okay what I'll
do then if none um is a dial in when the circuit sorry when the circuit port how much are
it when the circuit uh how much are they you mean the cost yeah circuit boards I the circuit boards
I saw for four bucks a piece and the uh the parallel sorry all right well I'm hearing a pretty
severe echo here all of a sudden okay it's gone yeah I sell the circuit boards for four dollars
a piece and the pre program picks along with a little uh 20 megahertz resonator it's a little
it's basically a crystal that sets the frequency standard for it I sell those as a pair of
for four dollars also and three bucks I think for mailing or something like that so uh do have a
stack of them left and uh not sure little happen when they're gone but I've got quite a few
you can around yet so for those interested that's roughly what what it would cost I think to build
the box it would be probably another another 20 bucks apart from did you key your a local electronics
supplier they're all very common parts are given the board and the and the pick itself
any other questions okay I'm going to jump off here and uh dial into the server and I'll
three party it in you'll hear me giving a demonstrate uh basically an explanation of would you
adhere one dial in I'll probably jump out of that and uh it'll go directly into a trunk that
presents a a ring back a ringing sound the way you would make a uh blue box called typically
is to dial an 800 number and while it was ringing you would hold the blue box up to the mouthpiece
and play the 2600 hertz tone to seize the trunk and I will demonstrate doing that so uh bear with
me a second I'm going to jump off here and try to link in the the server
last update Tuesday August 12 2008 to edit this messaging with directly to a trunk
press touch tone so right now we're hearing my presentation uh well the audio level at
here with star and a pound somebody can jump in can you guys hear them we'll hear mf tones
followed by a ring yeah okay yeah you are now connected I'm going to I'm going to bypass the
recording by hitting zero an early drop of sound or sound so we hear some mf digits and now we'll
hear a constant ringing the ringing will eventually time out and you can actually seize the trunk
at any point now what I'm going to do is play 2600 when I when I stop playing 2600 listen for the
wink back it's it's fairly subtle but you should be able to hear it did you hear it
now we're going to hear a recording in a second let me let that go
you have dialed two pound is not available now what happened is it heard my voice and
interpret that as some random digits so now we're still sitting on the trunk and you can probably
hear the buzz in the background if you listen that buzzing is actually the filtered 2600 hertz
coming back from the far side of the trunk now what happens is when I read when you after the
wink back is heard that means that a mf receiver is attached to the far end and is ready to
hear mf digits if you don't dial anything in within five seconds the trunk will detect that
and time out the trunks don't let you hold them up too long back in the 70s the real trunks and
I've emulated that so I think you'll hear probably a Jane Barbie recording if we're real quiet
so I'll let it time out and just demonstrate that
I'm sorry you're called did not go through but you hang up please and try again this is a recording
and now we're back on the trunk of we would have to receive it again to try to put another
receiver on so the mf receiver gets released just before that recording comes on with a few
few seconds of reorder tone after it so that's pretty much how it actually would work before if
you didn't dial quickly enough or if your mf digits were mangled you would get that type of
recording or something similar to it now what I have is internally on the asterisk
server that's connected here I have a series of internally recordings that can be accessed
using three digit codes so one of the things that has been quite popular especially with the
cnet the collectors network people are what I've done is taken the phone trips recordings from
evendorbell's phone trips website digitize them and put them up on various extensions or numbers
that can be blue boxed into and I've got the full length recordings on there so it is possible
to dial in and actually listen to the whole evendorbell one so what I'm going to do now is dial
cape I'll hit 2600 we'll get the link back I'll dial kp 112 start keep pulse was the tone that
was necessary to initiate a dialing sequence that indicate to the switch that digits were going
to follow and start was used to terminate the digit sequence and that was necessary of course
because the number of digits you could dial was variable so 112 is the code for the evendorbell
classic tandem standing classic tandem stacking tape so I will I will dial that
the following telephone recordings were made by Ben now what I've done is I put a series of
of of authentic old ring bag tones on there to try to make it sound as much like an old
a call go back and forth across an old old phone system is possibly and I think it adds to the
realism I do rotate through different ring bag tones so try that already the connection you get
will try a different one on this or an average conversation now I can blow this call off by playing
2600 which will hang up and then see that you don't really feel the depth of the
well here we go again with another in this and now we're on a different
of a recording I also have a couple of weird phrases from the asterisk sound library that
can be accessed for getting your tone tone levels correct and you're playing around with it
I'll play back one of those will blow up and off here and then with Ben
dial into one of the test record by the time you heard it much
we apologize we those have eaten our phone systems
well for some reason they've got that in the standard asterisk sound library I have no idea
why it would be used but it is there so I thought it was kind of interesting to put some of the
goofier ones on there for pulling around with I have another recording I have that's quite
popular is the Emmanuel Goldstein from 2600 magazine and off the hook radio show I have a
interview he did with dry bubbles that is just excellent back in the early 90s and we'll dial that
back in the 50s I really do credit him with being one of the original phone freaks and he
figured a lot of it out just using intellect and experimentation and a lot of time so a real
real a real freaker in the best sense of word in my opinion one other feature I have here also
is a conference bridge that's accessible so multiple blue box users let me get off here
so multiple users can dial in and I've made the code for that 2111
I'm sorry you're called did not go through well you hang up please and try again this is a
recording if you remember the old escuer article article 2111 was a code that would access a
conference bridge that was in the Vancouver Steptam at the time back in the 70s and it was one of
the most popular and well-known meeting places for phone freaks to get together so it was a really
a predecessor of this of of of the conference bridge we're using today we'll access that just
briefly you are currently the only person in this conference and we're just in a standard
asterisk bridge at this point we'll blow that off now back in the day the phone company used
internal codes for operators to contact other operators and other internal telephone company
functions one of the codes that could be used by the operator was 131 131 was the internal code
for our directory assistance so you could dial for example kp 216 what number you have dial 16121111 is
not available okay so you could dial kp an area code and then 131 to access the directory
assistance operator for a given area code so I have that code mapped to group 411 so if you
were to dial kp 131 start you would go to directory assistance in this case group 411 now you
can also proceed that code with any area code it goes the same place but I have the system
program to accept an area code to make it a bit more realistic so in this case I'll use area code
216 and then 131 and then start to to access the directory assistance function
calls recorded google say the business and the city
so again trying to try to try to to be as faithful as possible in spirit to some of the original
codes the number you have dialed is not in service please check a number and try again
again the system responding to my voice another internal code that the phone company would use
is 121 that was for the inward operator associated with an area so if a person was having trouble
making a phone call in indescribable the the operator who is assisting the customer would
dial kp 312 121 start 312 being the area code for Chicago at the time and 121 being the inward
operator I have that mapped to bring a local phone here in my switch room in the basement where
I'm sitting right now it also rings my cell phone so if somebody wants to talk to me being the
inward operator they they can use that so we'll demonstrate that you can hear it ringing my
I do have a couple of other external numbers that are connected in addition to the two that
I demonstrated there I do have a number you have dialed two two pound is not available I do have a
direct shift connection into telefree that can be dialed using a blue box that's with kp 777 start
and that's not a telephone code it's just a code that I happen to pick so we'll get that in try
a band in all home yeah now we're direct connected into telefree thank you for calling
with all the with all the 300 a waste mail box and a pound of a breast pound for advanced boxes
I'm sorry you're called did not go through but you hang up please and try again this is a recording
now the final probably coolest feature of the system is that I do allow people to make phone calls
into the pstm just like the old blue box system a world so if you see as a trunk you can dial kp
plus 10 digits plus start and that can be any phone number in the u.s. or canada and it'll actually
go through it is it is time limited and I don't guarantee it will be completely private it is
subject to monitoring just to discourage abuse but I do allow people to make calls and the calls
will complete and you can carry on the two-way conversation and pull around with it and blow it
off the 26th hundred and impress your friends and everything so I do allow it and in three years
I've had really almost zero problems with abuse and the cost has been so minimal I really haven't
had to ask people to kick in any money for it so as long as it stays that way I've had no problem
keeping that accessible so what I'm going to do is actually dial a number out on the pstm in this
case I'll call the u.s. naval observatory master clock in Fort Collins Colorado so again it's kp
10 digits without without a leading one just 10 digits like the old days and let's start and this
is what a phone freak would actually do after he sees the line so you can call into the system make
a call blow it off with 2600 redirected to another number without actually hanging up and starting
which is exactly the way it works back in the 70s we'll try that number
so
u.s. naval observatory master clock at the tone mountain daylight time 16 hours 58 minutes 55 seconds
universal time 22 and we'll blow that off at 2600 exactly and we got the wink back we'll let
that time out and then I'll move on to the next part of the presentation the number you have
dial seven four one is not available now one kind of cool thing that was real popular for
Humphreicks to do back in the 70s was to do something called tandem stacking and the way certain
switches worked back in the 70s is it was possible to use routing codes to dial into one switch
and to route the call to a second switch and then loop that back and forth between the two
switches multiple times and it was possible up to the limits of the audio quality of the line
to actually busy out a trunk route between two cities and for that reason the bell system
security people really really really did not like people doing it now because of because of
various restrictions on the technique it really wasn't possible to do any serious damage to the
network because of the rerouting capabilities of the early network but it really had the FBI
running scared when they found people were doing this and it was probably the thing that really
brought the heavy hands below down on Humphreicks as much as anything else now tandem stacking is
sort of possible in the system but I have to use if you've heard the classic tandem stacking
phone tricks recording you know how it was done for real but I can do here is I can
but I what I can do is dial into a number on my box that will return a dial tone that
accesses the switching train on the asterisk bus now the reason I have to do that is to try to stack
using asterisk isn't really possible because asterisk will not just seize a line and dial nothing
on it and that's really what you require to do stacking so what I've done in instead is I've set
up a system that routes through the SF trunks gives you a dial tone and you can dial the same
access number over and over again and every time you dial it it loops through another member of
those 24 trunks that I've set up here so you can stack up to 24 trunks by repeatedly
dialing 2602 which is the code number for for stacking so the first time you dial 2602 I use the
blue box but thereafter I use touchtones to do it and every time I hit 2602 I get another dial
tone and I'm actually stacking through the 2600 controlled trunks and it allows you to do some
interesting things on the terminating side so I'll demonstrate on what it sounds like on the
originating side and and then I'll try to do it dialing into this bridge on the terminating
side which is where you can hear some of the stuff so let me let me try it on the terminating
side so I'm going to dial Kp 2602 star it and that'll give me a dial tone and thereafter I'm
going to use the touchtone pad on the phone here to to stack a number of trunks repeatedly so let's
give it a try
that's okay we've gotten one link this will be the second stack
if that actually MFing 2602 under the trunks to pick up the next one
I'll do it again we're on our current stack
and I'll do it once more and after this one I'm going to actually dial a recording
through the stack of about 5 or 6 trunks that I've got stacked up here
so there's nothing really very extraordinary about it I mean it sounds exactly the same to us
as we're dialing into everything it's actually looping through a stack of fibers and trunks
with the phone so they don't think you'd really hear some degradation in audio quality
I can't do anything to interest with the kind of the original side let me blow you
really you would either call it so we've disconnected it now what I would like to do is
the number you have dialed is not in service please check the number and try again
uh put the phone down here for a second and using a second line here on my desk I'm going to
build a stack of similar to what I just did except the last number that I dial is going to be
the conference bridge and I'm going to so I don't get a feedback loop on it and I'm going to have
to unplug my handset here but I'm going to leave here for about a minute or two so if the moderator
wants to say anything feel free and the next time you hear my voice I'll be coming in over the
stack but on the terminating side and then I'll be able to show you some kind of interesting tricks
that can be done with it so if you forgive me I'm going to be gone here for about a minute so if
the moderator wants to fill the empty space with something that would be great
all right cool time to solve so yeah we're horrible at solving
so how's the weather up there
hmm
the same for us and moves up
what do you need to do to do we need some like hold music to play right now that's
all right it's going to be like the part of the recording that we edit out yeah
now you can't edit out anything that would take away the experience
well I think about putting on like a laser or something I'm like if you have more than
four seconds to sound to the like all right you don't recording
now think about it it's just like a regular conference those huge long periods of silence
that everybody just so enjoys oh yeah exactly exactly present office I mean we he didn't even
have to be you know silent he just we're just doing that to help the authenticity
exactly it's not a true I'll find a conference unless it does long awkward pause oh yeah awkward pause
new color hello yeah this is me I'm this is Don I'm calling back I'm calling into the stack now
so I've got probably five or six trunk stacked up or looped internally within the switch just
trunks that I've got and now what you're hearing is the terminating site of that stack before
we were hearing what it sounded like on the originating site now one thing Evan Dorbal did in his
classic tandem stacking tape is he was able to flash the switch hook and the supervision because
it used relays would be delayed with each loop through the system you can actually hear the relays
and the chips as as the tones propagated through the sister is the the DC act oh we lost them
here now it's really a real conference I know right
what I want to take him to that if I get this hopefully I guess that's our first disaster for the
whole conference uh besides the uh little minor three weighing difficulties yeah I've been
thoroughly enjoying this this is about as enjoyable as fiber optics uh speech at hope
yeah yeah you know I think I thought our first real problems can be like a mill water and echo or
something so you know the fact we have a good idea yeah yeah the fact we haven't had that yet
I guess that's a good sign it is a very good sign um just hope Don realizes that uh he's
disconnected and can reconnect unfortunately we don't have any way of like uh instant messaging
everything oh there we go don't thank you I guess not no this is hypercard I'm just merging
in the cold bin okay cool I will base with how quiet everyone's been well that's because like two
of the conferences are muted huh gotcha gotcha I guess that makes sense you know we just um you
know him or something actually uh I'm muted those when uh he dropped off can I figure well
what people talk about him you guys hear me okay we're back hello we're back okay can you hear me
yeah you like it yeah we're here okay okay so what I'm gonna do is hang up uh listen for the
chiefs and uh that'll be the stack tearing down yeah and I'm back on I'm sorry you're called
did not go through you hang up please and try again this is a recording we're the chiefs
audible when I disconnect okay cool so anyway so that's stacking uh cute trick but uh many people
have tried to play with it uh the last thing in my talk that I like to demo is um doing something
oven doorbell did again in his phone trips tapes and that is he was able to set up a series of
interconnecting switches by dialing various trunk access codes and using a technique called guard
banding when you try to link a lot of switches together using a MF the problem is um he runs into
the same problem I did on stacking uh every time he had 2600 it drops you back to the first
first 2600 link and uh chain that you're trying to put together so he's got to use some special
techniques to do it so what I'm going to do here is dial into the CNET the collectors network
system and I'm going to actually raw I'm going to actually build up a stack of of calls linking
through various electron mechanical switches that are in people's basements all over the country
I'm going to send it overseas to England uh and go through a switch over there and then back to
the states and finally I'll terminate the call on uh on one of my recordings on the switch the
first link in the first switch I go to I'm going to set up again with uh with the blue box
but thereafter because uh other switches besides mine do not respond to 2600 and MF I'm going to use
special numbers they have set up their recent dial tone so to build the stack primarily I'll be
using touch tone here and I'll try to explain what I'm doing as I actually build it so my goal is
if you get hate switches on here and uh we'll uh we'll see what it sounds like when I when I think
you'll be able to hear the degraded audio after bouncing it around the United States and uh
and overseas so let me initiate the stack by uh by dialing into a switch up in Minnesota and we'll
do that right now
now try this again
now we're going to go into a real mechanical switch
and we're going to dial 9 to get an outside line on the switch
and we're going to go into another switch in Alabama
and we're going to go back into another lecture mechanical switch
there's a dial tone will dial 9 for an outside line
and we're going to dial into my project MF box
and hear the audio degrading now we're going to loop it through my box a few times
and then we'll send it overseas to England to a switch set up in a guy's basement over there
now we'll go back to the states to a molecular mechanical switch
9 for an outside line
and we'll finally dial a recording on my own ask box here and we'll see how that sounds
so at this point we're being around the world uh quite a quite a distance uh
linking together real electro mechanical switches and people's basements pretty much like
uh heaven did on the on some of the routing tapes that he did and you can probably hear the audio
very very low level in the background because of uh because of all the attenuation
and uh now when i blow 2600 what will happen is because the only link here is is 2600 controlled
is the original one when i use the blue box it'll drop us back to my it'll disconnect
all of these switches so all around the country all of the steppers are resetting and making a lot
of noise and all these links are getting torn down one by one every when i hit the 2600 and we'll
drop back to my switch again on the first link and now we're back here we could dial another call
at this point if we wish to the number you have dialed 7-1-1 pound is not available
so that's about it it just shows uh kind of showcases the system that i've got set up again
this is publicly accessible and any of you guys are perfectly welcome to try it anytime
i think that the moderator moderator is going to publish the routings and the numbers i actually
use in this demonstration so feel free to email me from the website and i'd be happy to answer any
questions at this point or by email thank you for the attention and i really enjoyed giving
the presentation yeah we'll have a copy of the entire outline of his speech on the site so
sometimes you guys want to have you know if you guys want to try and emulate these are the results
perfectly possible uh we'll have all the numbers all the extensions everything like that
and then we'll point to his website so you can download the blue box software if you need it
things like that maybe hey so df99 before you uh before you hop off are you going to be saying
for a bit uh yeah i plan on listening in to listen to background on the speakers all right great
if i'm any of your help for one of the presentations uh no problem yeah i can
all right yeah i can three party interview okay thanks guys enjoyed it
yeah thank you um all right our next speech is uh oil when you think
thank you for listening to act of public radio hpr sponsored by caro.net so head on over to
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