TELECOM Digest OnLine - Sorted: Telecom Archives Reprint - Prison Phone Technology

Telecom Archives Reprint - Prison Phone Technology

TELECOM Digest Editor (
Sat, 28 Jan 2006 21:32:53 EST

Ten years ago in this column, I printed an essay from Tom Farley on
the topic of Prison Phone Technology. On a cold, damp, Saturday night
here (winter has _finally_ come to Independence this year, it seems)
I thought it might be a fun item to review again, especially for our
readers who were not even on line here ten years ago.

Date: Wed, 2 Oct 1996 16:00:46 -0400 (EDT)
From: (TELECOM Digest Editor)
Subject: Prison Phone Technology

Tom Farley is another great member of our online community who writes
a print journal from time to time known as {Private Line}. I shared
his most recent issue with Digest readers recently and now I have
another excellent report from Tom, this time on telephones in prisons.

Without wasting any more bandwidth, let's read it!


From: Tom Farley <>
Subject: Prison Phone Technology
Date: Wed, 2 Oct 96 14:31:56 -0500
Organization: Delphi ( email, 800-695-4005 voice)

Hello, Pat. Here's something from my latest e-zine. I can e-mail people
a copy of the ezine although it should be up at soon.

Best wishes, Tom Farley

by Tom Farley -- --
A. A brief overview
B. Three different call processing approaches
1. Class of service approach
2. Generic switch utilizing custom software
a. Close up of one switch: NACT's 120LCX
3. Dedicated system using PC technology
4. Typical Call processors' anti-fraud features
a. Call blocking on a permanent basis
b. Call blocking on an as needed basis
c. Limiting long distance carriers
d. Flash hook prevention
e. Rotary dial acceptance
f. Limiting automated message attempts
g. Conference call prevention
C. The federal Inmate Telephone System (ITS)
1. Introduction
2. Letter from jail
3. Discussion and speculation
4. Federal Bureau of Prison (B.OP.) Time Line
5. Discussion continues
6. ITS Account Report
7. A report on ITS from Jail
8. Real short conclusion
9. Bibliography

A. General Overview

The prison phone business is big and getting bigger. At least
50,000 inmate phones now exist with more being added all the time.
By comparison, colleges account for 60,000 public phones and hotels
and motels 80,000. [1] Phone companies pay big commissions to
states and counties to service the rapidly growing prison market.
The decades old practice of letting inmates call collect to any
number they wish is now being replaced by allowing collect calling
or direct dialing to pre-selected numbers. Just how that is
accomplished is the focus of this article.

Prison phone systems come in a bewildering number of shapes
and sizes. County, state and some Federal prisons configure their
operations for their requirements, consequently, there are no
standards, much like all PBX's vary widely in features and operating
methods. But like PBX's, there are some features common to all
"inmate call control technologies."

At the very least, a prison phone system uses a call processor
to approve and place the call, surveillance equipment to monitor it,
and recording equipment to archive the conversation. Only smaller
counties and, curiously, the Texas Department of Criminal
Justice, "the largest state prison system on earth, still unlock
the cells and let prisoners use a phone on someone's desk, a la
Barney Fife." (2) In past years prisoners could call collect to anyone
they wished. The new trend, though, is toward allowing direct or
collect calls to pre-approved numbers. The most controversial
approach is a pre-approved number scheme, as practiced by the
federal Inmate Telephone System (ITS). But before we look at ITS,
let's look at the technology state and county prisons use to process
automated collect calls.

B. Three approaches to call processing

While line based call blocking is an effective solution for some
facilities, most county and state prisons use a call processor to
approve and place calls. There are two approaches. The first method
employs a pre-existing switch using custom software written for
the prison industry and quite often for the individual facility itself.
Switch based platforms excel at supporting the greatest number of
ports (sometimes to 8,000). The other approach uses a dedicated
system based on PC or microprocessor technology. PC-based
platforms shine at providing flexibility. Figure on stand alone
switches costing from $160,000 to $700,000, compared to PC-
platforms starting around $60,000 with only 96 ports or 48
channels. [3] Let's first look at what a telco can do and then we'll
look at call processors.

1. Class of service approach

Large and small telcos offer many kinds of call blocking to
institutions. The advantage is simplicity. Order from your local
phone company and pay by the month. Pacific Bell calls their two
offerings the "COPT (Customer Owned Pay Telephone) Inmate Line"
and the "COPT Inmate Collect Only Line." [4] The COPT Inmate Line is
a low security offering, with only 900/976 and international direct
distance dialing (IDDD) permanently blocked. 'O+' calls are screened
for collect only. All other calls, including local, '411', '611' , '911'
'0-' (operator dialed) and so on must be blocked with customer
owned equipment. Their COPT Inmate Collect Only Line, by
comparison, costs more but blocks all of the above calls, at least
over Pacific Bell's network. Line based call blocking may be good to
have, however, it can't replace a prison's call processor.

2. Generic switch using custom software.

Switches like the Summa Four, Excell, Harris 20/20 are often
used to managing prison calls. National Applied Computer Technology
(NACT), for example, sells a switch called the LCX 120C switching
system. [4] It's a tandem digital switch, often used by long distance
carriers, prepaid calling card sellers, payphone route handlers and
other service providers. The 120C is a medium to large trunk switch,
capable of putting long distance traffic out to the toll network
without going through the local central office first. It's a generic
switch, therefore, with software making the difference. NACT is
heavily involved in the correctional industry. Let's look a little more
closely at this switch, since it is so often used in prisons and other
high fraud locations.

a. Close up of one switch: NACT's LCX120C

Although I do not have the name of the operator, a NACT
LCX120C is currently operated by a company which manages or owns
over 2,500 COCOTs in New York City. 1+, 0+ and 0- calls are
processed through the switch and all traffic is scrutinized by
NACT's proprietary Control and Validation Unit (CVU). Most software,
by the way, is developed in "C". NACT claims fraud losses will drop
from 20% on average to 0.5 percent and the return on investment for
this operator was only six weeks. Perhaps.

The cabinet housing the switch stands three feet tall and two
feet wide. A clear plexiglass door covers the electronic bay housing
the electronics. Two 125 cfm fans keep the air moving. The control
and validation unit (CVU) stands at the top of the assembly. The CVU
is the primary processor, equipped with dual 330/520 MB hardrives
and a 250 MB cartridge tape drive. Using older but serviceable
technology, the processor is an MC680x0, utilizing 8 megs of ram
and drawing on a 400 watt power supply. The CVU does validation
and controls the trunk control unit (TCU) below it.

Up to four trunk control units can be supported, each TCU
controlling 120 ports (60 talk paths). The TCUs contain "processor
and trunk control cards to handle line signalling, send/receive
digits, and interface with the CPU." Each TCU utilizes a "realtime
industrial processor", 128 Kb of RAM, 80 KB of ROM and a 300 watt
power supply. An uninteruuptible power supply sits below the TCU
and a remote diagnostics system, with a modem, of course, sits
below that.[5] Add an administration workstation and a printer and
you're ready to roll.

2. Dedicated system using PC technology

The other approach to prison call processing uses a dedicated
system, often based on PC or microprocessor hardware. Such a beast
will use a 486 processor or a Pentium, typically running under DOS
rather than UNIX. TELEQUIP, CPDI and others use this approach. [6]
TELEQUIP's ACP-4000 (Automated Call Processor (R)) is marketed
just to correctional facilities. That might make it simpler to install.
TELEQUIP boasts that "ACP installation is the easiest in the
industry. No wall space or card racks! Simple plug-and-play is
standard. Set the ACP anywhere on-site, connect one cable to a 66
block, plug in the power and your ACP is processing inmate calls!" [7]
Wonderful. N.A.C.T., by comparison, says six weeks are required to
install their switch. TELEQUIP says their equipment services 8,000
prison lines and six state contracts. That's a pretty large slice of
the prison pie. But for variety, let's take a look at CPDI's offering to
get an idea of a PC-platform based switch.

b. Close up look at a PC-based switch

CPDI's PC-switch approach is typical. It relies on a file server,
a card processor, a workstation, Dialogic telephone interface cards,
a Novel local area network, a hub and some proprietary software. [8]
The file server is actually a souped up PC, a computer with file
management software, voice boards for prompts and a big hard drive.
T1 lines usually terminate directly into the card processors. Each
processor supports 48 ports or 24 channels. A tape backup and a
hard drive backup are usually standard, indeed, a redundant file
server is often used in case of failure. The administration
workstation may have a modem and a dial up remote access port.

So what do these two kinds of systems have in common?
Plenty, especially when it comes to anti-fraud features.

3. Call processors' anti-fraud features

Many state and county prison calls are dialed collect from a
pre-approved list. Allowing and supervising calls from hundreds or
possibly thousands of prisoners at an institution requires a fraud
resistant automated collect calling system. Everett Castor, switch
operations manager for N.A.C.T says "You can't possibly simulate in a
lab everything an inmate can think to do." [9] Here's a list of
features a modern processor may have:

a. Call blocking on a permanent basis -- Most
inmates are not allowed to talk to a live operator
of any sort. In addition, 700, 800, 900 and 950
services are all permanently blocked. "Country codes,
information digits, NPAs (area codes), third party
numbers" can also be shut down.

b. Call blocking on an as needed basis -- Inmates
and their compatriots are notorious for their
ability to find home phone numbers of guards,
wardens and family members of same. Witnesses,
judges and many others are also targets. Most systems
accommodate nearly limitless amounts of non-dialable
numbers. This does not prevent a third party, though,
from manually bridging a call.

c. Limiting long distance carriers -- Most systems
now use one carrier, keeping inmates from switching, for
better or worse, to another LD provider.' [10]

d. Flash hook prevention -- keeps inmates from
breaking out of of a call and dialing a new number.
[11] This was a problem with older analog
processors which were built along PBX lines.

e. Rotary dial acceptance -- Some systems allow a
rotary dialed party to signal collect acceptance by
holding the line, however, this normally requires the
switch to be programmed for this ahead of time.

f. Limiting automated message attempts -- Like many of
us, inmates try to send coded messages with an
automated collect system. This feature limits attempts
to a certain number within a certain amount of time,
keyed to the inmates' account number.

g. Reverse battery supervision -- Disables keypad after
destination number is dialed. Prevents fun and
games and possibly getting a new dial tone.
Pressing different buttons on the keypad while an
automated collect system worked may have
allowed an unrestricted dial tone in older systems.

h. Three way call prevention -- TELEQUIP claims near
100% 3-way call prevention with their patented ACP
processor. They go on to say that AT&T's Inmate
Processing System deters only 93% of such attempts. I
do not see how manually bridging a call can be stopped.
It is also possible that call forwarding or foreign
exchange circuits could circumvent this.

i. Call limitations -- allows an institution to limit calls
by length, billing type, dollar amount and so on. May
prevent a huge bill from being placed to a subscriber who
has no intention of paying.

D. The Federal Inmate Telephone System (ITS)

1. An introduction

The Federal Bureau of Prisons (B.O.P.) incarcerates
approximately 100,000 prisoners at 84 institutions across the
country. Fully a quarter of that population are foreign nationals,
willing and often able to spend big bucks to call home. This captive
market might seem ideal for private competition, with hundreds of
long distance companies bidding for a Federal contract. Oddly
enough, though, the U.S. still carries calls themselves over the
government's normal FTS2000 network. That's composed of,
essentially, heavily discounted Sprint lines. (Local telephone
companies handle local calls). [13] A new contract, however, will be
awarded for this traffic due to a court settlement, indeed, a whole
new inmate telephone system will be developed in the next year or
two. For now, though, the B.O.P. continues to manage things their own
way. So what's going on here? And what kind of technology do the
Feds use to process these calls? Before we answer those questions,
though, let's take a break and look at the letter that got this article

2. Letter from jail

March 12, 1996

private line journal
P.O. Box 1059
Isleton, CA

Re: A "Beseeching", of sorts . . .

As may be evident, I am currently incarcerated within a federal
correctional center in Coleman, Florida. I have been placed in this
hell hole due to ideas run-afoul . . . I am here for wire fraud. It
seems that I may have gotten ahead of myself in that I "accidentally"
wired money from a corporation's account that I neither worked for,
nor had the authorization to be meddling with. Never-the-less, some
funds, as I said before, "accidentally" ended up in my account (which
was opened in another name, by the way -- I am not totally lame!).

Anyhow, I would hope that I may be able to convince you to send me a
couple of your back issues, or better yet, a subscription to your fine
journal? I await your reply with high hopes.

name withheld

3. Discussion

Damn that wire fraud! Turns out our man is the author of,
appropriately enough, _Credit Card Fraud and Toll Fraud Issues_, a
slim tome detailing how "scam artists can take advantage of you
without your knowledge." Great. In any case, I sent him a copy
of _private line_ and he replied with all sorts of interesting
information on the Inmate Telephone System.

ITS is a switch based system controlled by a UNIX workstation
at 41 federal penitentiaries. I doubt a switch sits at each facility,
however, that is certainly possible. But remember, a switch like a
N.A.C.T. can sit anywhere in the United States and take calls. The
traffic simply has to be routed to it. You could even own a switch
and have it located at N.A.C.T.'s headquarters in Utah, just so that it
gets around the clock attention. It would be natural, though, that
some sort of G.T.E. switching is employed since G.T.E. helped develop
I.T.S. Maybe in Texas? Collect calls that are authorized use AT&T's
automated collect call program. [14]

In accordance with a settlement last year, "prison officials
have now agreed to tie their rates to those of state prisons, which
are controlled by state utility boards."[15] That might cut down on
complaints about high costs, especially overseas calls. Rates like
$9.99 a minute to Vietnam were not uncommon. Even domestic calls
are sufficiently high that a foreign exchange circuit may be less
expensive to arrange rather than paying for direct dialing. (I've paid
as high as 61 cents a minute to accept an ITS call from Florida in
the middle of the day.) Whether the ITS officer in each prison would
allow this is a whole different question, since the whole system is
in flux and because each facility is allowed a great deal of leeway in
deciding its rules. As an example 38 facilities allow only direct
dialing to pre-approved numbers, 28 still provide direct calling only
and 18 provide both. The settlement does allow 120 minutes of
collect calling to all inmates, no matter what the policy is at a
particular institution.

Anti-fraud features are basically the same as noted under '3'
above. 3-way calling is definitely frowned upon. As one prisoner
notes "the ITS system (through GTE/OPUS's proprietary specialized
programming) detects such calls in real time, cuts off the inmate-
caller, flags the inmates PAC and records the telephone number the
inmate was connected to during the 3-way calling attempt."[16]

The Bureau of Prisons originated the Inmate Telephone System
in 1990, implemented part of it through 1993 and watched as it fell
apart in 1995. ITS lingers on at many institutions, but only until the
entire system is scrapped after a new contract is awarded. That may
take another year to let. Maybe two. The cornerstone of the system,
direct dialing to pre-approved numbers has been heavily modified.
The funding method, whereby the B.O.P. raided an inmate welfare
fund to install the system, without having to officially publish their
rules or intent, has been crushed, with Federal officials having
returned $4,000,000 in mis-appropriated funds. What a mess. Take a
look at the time line that follows:

4. Federal Bureau of Prison (B.OP.) Time Line

Pre-1973 -- Each institution's warden sets phone policy
1973 -- B.O.P. sets uniform national phone policy
6/29/1979 -- B.O.P. issues final Rule (44FR 38249) for policy
6/1/1983 -- B.O.P. amends 1979 rule (44FR 24622)
1990 -- B.O.P. conceives Inmate Telephone System
1991 -- GTE & OPUS begins installing ITS at certain prisons.
4/1992 -- B.O.P. starts charging AT&T rates plus 75 cents a call.
7/1993 -- An anonymous LD carrier sponsors class action suit
against B.O.P.
8/1993 -- B.O.P. stops installing ITS after 41 facilities due to
court injunction.
4/1994 -- B.O.P. admits official policy not often practiced.
4/1994 -- AT&T submits unsolicited bid to develop new system.
4/1994 -- Final rule published in the Congressional Record.
5/1995 -- Mediation begins, seeking to resolve problems.
8/2/95 -- Settlement reached.

5. Discussion continues

ITS was supposedly implemented to provide better security
and to enable prisoners to better account for their money. The
security angle seems spurious in light of existing call processors
that offer excellent results. Money management seems odd as well.
Direct dialing meant that prisoners needed to pay for calls out of
their prison accounts. Yet B.O.P. officials would often take money
sent by relatives and friends to cover phone expenses, in order to
recover other debts owed by the prisoner. Endless arguments and
excitement followed. Prisoners thought long distance costs were too
high. Long distance companies felt shut out and the courts were also
unhappy. Without going further into the history and machinations of
all of this, [17] let's look at how ITS works in practice. Before we
get an account from a _private line_ reader in jail, though, let's look
at what a typical account report looks like, just so we get familiar
with the terms. A register number, by the way, is like a prisoner's
serial number . . .:

6. ITS Account Report

Inmate Telephone Account Report

Page 1of 1 Report Date Jan. 12, 1996 12:12 /dev/ttyi1f

Register Inmate Phone Access Date
Number Name Code Entered

03496823 Louis Freeh 478274228 25-FEB-96

Inmate Dialing Instructions

Inmate Telephone System (ITS)

To place:

-- A Local Call:
1. Listen for the dial tone.
2. Enter the seven digit telephone number.
4. Enter your Phone Access Code (PAC).
Example: 555-1234-478274228

-- A Long Distance Call:
1. Listen for the dial tone.
2. Enter 1, area code and telephone number.
4. Enter your Phone Access Code (PAC).
Example: 1-202-555-1234-478274228

-- An International Call:
1. Listen for the dial tone.
2. Enter 011, country code and telephone number.
4. Enter your Phone Access Code (PAC).
Example: 011-24-335937-478274228

To obtain your ITS account balance and the cost of your last call:
I. Listen for the dial tone.
2. Enter 118, then enter your Phone Access Code (PAC).
Example 118-478274228


7. A report on ITS from Jail

A hacker at Lompoc writes _private line_ to say:

"ITS is pretty crappy. All my phone numbers have to be
submitted to my counselor prior to calling (up to 30 numbers). In a
few days the numbers are verified and put on my phone list. Each
inmate is assigned a 10 digit pin when they first arrive.

The phones are like those information phones at airports.
They're all in a row, about 25 of them with the small partition
dividing each phone. I don't know if it's important but the handsets
all smell like shit. When the handset is lifted you are greeted by a
standard dialtone. After you dial the number you get a second
dialtone. Then you enter the PIN and wait for validation.

The whole system is pretty Mickey Mouse and the cross talk is
almost unbearable. Throughout your conversation you can hear DTMF
tones from the neighboring phones. Each call is limited to 15
minutes but you can call back immediately if no one is waiting. When
you get down to your final minute they drop carrier for a split
second to warn you have 15 seconds left.

If a foreign dialtone or ring is detected you are dropped
immediately. This is to prevent people from three-waying phone
calls. It's easily corrected if the receiving party places a call, waits
for an answer and then bridges the call. All calls are monitored,
most likely recorded, in case you conspire to commit another crime
over the phone. The Feds are always looking for a new indictment.

Everything is handled by a machine they have on the compound.
It's some UNIX box that treats each phone as /dev/???. [18] The only
numbers you can dial are those on your approved phone list. Thereby
eliminating the problem of people stealing kodez!, or dialing any
unauthorized numbers. ("O", 911, 800's, 700's, etc.)

Basically, it's run by a script . . . a person can pretty much
write the whole ITS in modem commands.

The system's primary concern is security with inmate's phone
calls as a secondary function. The rates are similar to calling card
rates, a call to L.A. costs me $3.75 for 15 minutes. Interestingly it
costs the same to Sacramento . . ."

8. Real short conclusion

ITS seems like some bureaucrats 'better idea' gone seriously
astray. B.O.P's Request will be interesting to watch for in the next
year or so. They'll need to specify what kind of system they want so
that companies can bid on it. Lots of technical details should be
included. My guess is that they will go with more conventional
equipment and techniques -- I'm unsure if they can build on ITS
technology, no matter how well it works, since GTE and OPUS's
approach is proprietary. Hmm. Got any more information or personal
experience with prison phones? Send it in and I'll print it here.

9. --Bibliography--

[1] "Long Distance Runaround" _New York Newsday_ Michael Moss,
May 14, 1995

[2] 'Dialing For Dollars: Taxpayers Could Win Big With Prison Pay
Phones' _John Sharp Opinions and Editorials_ Undated :( John Sharp,
State Comptroller of Public Accounts (5k)

[3] "Calling Card Platforms -- The Intelligence Behind The Cards" Ed
Metcalf _Premier Telecard_ December 1995-January 1996 28
(+1(805) 547-8500 for Premier)

[4] Pacific Bell. For questions, try +1(415) 452-7455

[5] National Applied Computer Technology, 744 South 400 East,
Orem, Utah 84058 (801) 225-6248 FAX (801) 224-8456

[6] TELEQUIP Labs Inc., 1820 N. Greenville Ave., Suite 100
RIchardson, TX 75801 1(800) 329-3290; Communications Product
Development Incorporated 915 Broadway, Suite 100 Vancouver, WA
98660 (360) 694-2977 FAX (360) 694-2553

[7] TELEQUIP advertisement _Public Communications_ Volume 11,
No. 4 April, 1995 49. This ad extols the virtues of their patented
switch. This means you could do a patent search and read all about
it. Consult _private line_ No. 4 (Volume 2, No. 1 January/February
1995) for my lengthy article on patent searching.

[8] "Calling Card Platforms -- The Intelligence Behind The Cards"

[9] "LCX 120C A Success In Camden County Correctional Facility,"
_CCQ-Correctional Communications Quarterly_ April, 1994. I have a
reprint of this article, as supplied by N.A.C.T., however, I have no
further information on _CCQ._

[10] "Letter from Prison" _2600_ Winter 1992-93 (Volume Nine
Number Four )13

[11] CCQ ibid.

[12] Letter to the Editor by C. Rebel _2600_ Autumn 1990 (Volume 7,
Number 3) 29

[13] "Federal Prison Telephone Plan Stuck on Hold" _Legal Times_
Naftali Bendavid May, 22 1995 Well researched and balanced article
on ITS issues. +1(457-0686) 1730 'M' Street N.W., Suite 802
Washington, D.C. 20036

[14] Each time I've accepted a collect call from ITS the automated
voice announces "AT&T".

[15] "Plaintiffs, Feds Connect in Settlement; Inmates Laud Deal Over
Prison Phones" _Legal Times_ Naftali Bendavid August 14, 1995
Follow on to the article in 13 above.

[16] name withheld -- Personal correspondence

[17] B.O.P.'s point of view is contained in the Federal Code of
Regulations: 28 CFR 540 -- Telephone Regulations and Financial
Responsibility. Or look it up in the April 4, 1994 Federal Register.
It's the Big Kahuna of ITS documents, as far as rules, regs and
explanations go. Not much technical info, however, you may want to
look it up under this candidate for the longest URL:;1994_register/TEXT/100384/3=0%201003840%20/diska/wais/data/1994_register/fr0ap94dat022.txt;

[18] Peter Shipley offers this explanation of /dev/???:

A /dev/ is a path to a device kind of like COM1, COM2 and LPT1
under DOS. Think of COM1 as \dev\COM1 on your DOS box and if you do
a dir or c:\dev you will see a listing of cards and services you have
on your system, eg: (I made this list up)

c:> dir \dos

COM1 0 09-09-96 5:47p
COM2 0 09-09-96 5:47p
LPT1 0 09-09-96 5:47p
SOUND BST 0 09-09-96 5:48p
MOUSE MS 0 09-09-96 5:48p
SVGA 0 09-09-96 5:48p
KBD 0 09-09-96 5:48p
SCSIDISK 1 0 09-09-96 5:48p
SCSIDISK 2 0 09-09-96 5:48p
SCSITAPE 1 0 09-09-96 5:48p
SCSIROM 1 0 09-09-96 5:48p
FLOPPY 1 0 09-09-96 5:48p
FLOPPY 2 0 09-09-96 5:48p


[TELECOM Digest Editor's 1996 Note: Tom, thank you *very much* for
sharing this. This article will become a permanent file in the
Telecom Archives. Watch for it there soon. PAT]

[TELECOM Digest Editor's Note: Has the system changed very much, or
is it still as described? I do know that even from our local jail
here in Independence, accepting a collect call from an inmate -- the
only way the person call call -- is _quite_ expensive. PAT]

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