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Current issue : #11 | Release date : 1987-02-17 | Editor : Taran King
Index to Phrack ElevenTaran King
Phrack Pro-Phile VIII on Wizard of ArpanetTaran King
PACT: Prefix Access Code TranslatorThe Executioner
Hacking Voice Mail SystemsBlack Knight from 713
Simple Data Encryption or Digital Electronics 101The Leftist
AIS - Automatic Intercept SystemTaran King
Hacking Primos I, II, IIIEvil Jay
Telephone Signalling MethodsDoom Prophet
Cellular Spoofing By Electronic Serial Numbers donatedAmadeus
Busy Line VerificationPhantom Phreaker
Phrack World News XKnight Lightning
Phrack World News XIKnight Lightning
Title : AIS - Automatic Intercept System
Author : Taran King
                               ==Phrack Inc.==

                   Volume Two, Issue Eleven, Phile #6 of 12

                            Taran King Presents...

                       AIS - Automatic Intercept System

             The DAIS II System by Computer Consoles Incorporated

         Computer Consoles Incorporated (CCI) manufactures various hardware
appliances to be used in conjunction with phone companies switches as well as
other aspects of the companies' uses, plus computer systems such as their own
Unix-supporting systems.
         DAIS II is the Distributed Automatic Intercept System, which is the
system used to announce if the subscriber has dialed a non-working number.
This is what you hear, in action, when you dial a wrong number and get the 3
tones plus the announcement or the ONI (Operator Number Identification)
intercept operator ("What number did you dial?").
         The information from this file comes mostly from an instructional
manual sent to me by CCI, who can be reached at 800-833-7477 or 716-482-5000
directly, or may be written to at 97 Humbolt Street, Rochester, NY, 14609.

         Most definitely any person who has used a telephone in his life has,
by some means or another, come across the dreaded 3 tones, leading up to the
ever-so-cumbersome announcement telling of the disconnected or non-working
number.  This file will go into how the whole system works.
         After dialing the non-working number, the telco's Class 5 End Office
routes the call to DAIS II.

ANI Calls
         Provided that the End Office has Automatic Number Identification
(ANI) equipment, the equipment then identifies the digits of the called number
and sends them to the intercept system.
         The system receives the called number from the end office, retrieves
information for that number from the intercept database, formulates the
message, and delivers it to the customer in an automated announcement.  These
announcements can either be standardized or tailored to the independent
telephone companies' needs.  If further assistance is required, the caller can
then stay on the line and wait for an operator to come onto the line.

ONI Calls
         When the End Office is primitive, and they don't have the ANI
equipment to do the above ritual, operators are directly involved.  These
operators are also called into action when there is an ANI or DAIS II failure.
         When the ONI (Operator Number Identification) call comes in, DAIS II
routes the call to the operator.  The operator asks for the number that the
customer called and then keys it into her KDT (Keyboard Display Terminal).
After she hits the command key, the number's information is searched for in
the intercept database, the message is formulated, and the automated response
is announced.  Once again, if the caller needs further assistance, an operator
will return to the line to help the subscriber.

         Operators will return to the line for any number of reasons.  They
include the following:

Unsuccessful Searches - After DAIS II receives the called number from ANI
                        equipment or from an operator, it searches the
                        database to find the intercept message associated with
                        the telephone number.  The database contains all
                        10,000 line numbers for each exchange in the calling
                        area.  If the system cannot complete the search, the
                        number was either keyed in incorrectly or there is a
                        problem in the system.  The call is then routed to an
                        operator and displays the intercepted number
                        (including NPA) on the KDT screen along with a message
                        indicating why the search could not be completed.  If
                        the number was keyed in wrong, the operator will
                        correct the number, or else she will ask the
                        subscriber to re-dial the number.
Aborted Announcements - If a search is given successful but for one reason or
                        another the automated announcement cannot be given,
                        the call is routed to an operator.  The KDT display
                        shows the intercepted number, the appropriate
                        information for a verbal response, and the message,
                        "VERBAL REPORT."  In this case, the operator quotes
                        the message to the caller rather than activating the
                        automated response.
Reconnects            - If a customer remains on the line for more information
                        after receiving the automated announcement, the system
                        routes the call to an operator.  The operator's KDT
                        display shows the called number plus other pertinent
                        information given to the caller in the previous
                        announcement.  From here, the operator can respond
                        verbally to the customer's needs, or activate the
                        automated system again.  The DAIS II system allows up
                        to 4 reconnects per call, but the possible number of
                        reconnects available ranges from 0-3.  With 1
                        reconnect, the operator must report verbally.
Split Referrals       - If a number has been changed but replaced with two
                        numbers, this is called a "split referral."  When the
                        database finds 2 or more numbers, the DAIS II system
                        routes the customer to an operator, displaying the old
                        number and new listings on the KDT screen.  The
                        operator then asks which number they are looking for
                        and keys in the command key to activate the
                        announcement, or else they do the announcement

Operator Searches
         Situations may arise where the subscriber needs more information
than was given by the automated announcement, or believes the information to
be invalid.  DAIS II provides for operators to have access to both the
intercept and the DA databases at all times as long as the system
administrator, who judges the extent to which operators can use the
cross-search capability, allows it.

Components Of The System
         The telco's Class 5 End Offices contain switching equipment that
routes calls to DAIS II.  If the office has ANI equipment, the switch routes
the called digits to the intercept system in the form of multi-frequency
tones.  The end offices route calls to DAIS II on dedicated (direct) trunks.
These direct trunks can carry ANI traffic or ONI traffic, but not both.

         If trunk concentrators are used, the concentrator trunks to DAIS II
may carry ANI calls, ONI calls, or both, depending on the types of trunks
coming into the concentrators from the end offices.  The call is identified as
ANI or ONI through MF tones transmitted by the concentrators.

         If an operator must be involved (due to ONI or further assistance),
DAIS II routes the call to the telco's ACD (Automatic Call Distributor), which
is a switching device that routes calls to any available operator.

         The intercept data base resides on disk in the ARS (Audio Response
System).  ARS processors known as Audio Response Controllers (ARCs) search the
intercept database.  If a call requires an operator's services, the Marker
Decoder Unit (MDU) provides ACD routing information to the ARC.

         The DAIS II Automatic Intercept Communications Controllers (AICCs)
route messages between the ARCs and the DAIS II subsystems.  An intercept
subsystem that is housed at the same location as the database is called a
Colocated Automated Intercept System (CAIS).  A subsystem located at a
distance from the database is known as a Local Automated Intercept System
(LAIS).  Each subsystem can provide automated announcements without using
expensive trunking to route ANI calls to a centralized intercept office.  Only
calls that require operator assistance are routed on trunks to the ARS site.
Because those trunks are only held white the operator identifies the number
and are released before the announcement begins, trunk requirements are
reduced.  The automated announcement is always given by the intercept

         Each CAIS or LAIS site contains a Trunk Time Switch (TTS) and DAIS II
Audio Response Units (DARUs).  Intercept trunks from the concentrators and the
Class 5 End Offices terminate at the TTS.  When an ONI call comes in on one of
these trunks, the TTS routes it to the ACD.  When an ANI call comes in, the
TTS routes the called number to the ARC.  After the ARC retrieves the
appropriate message from the database, it sends that information back to the
TTS, which connects a DARU port to the trunk on which the call came in.  Then,
the DARU produces an automated announcement of the message and delivers it to
the caller.  ARS hardware generates only DA announcements whereas DAIS II
hardware generates only intercept announcements.

Automatic Intercept Communications Controller (AICC)
         The AICC routes messages between the ARC and the TTS.  Two units are
required to enhance system reliability.  Each pair of AICCs can communicate
with up to 4 CAIS or LAIS subsystems.

         The AICCs are similar to the Audio Communications Controllers (ACCs)
in the ARS system, but AICCs use a Bisynchronous Communications Module (BSCM)
instead of a LACIM.

         An AICC can be equipped with up to 8 BSCMs, each of which handles one
synchronous communication line to the TTS.  The BSCM models selected depend on
the location of the AICC with respect to the CAIS/LAIS sites.  Standard SLIMs
(Subscriber Line Interface Modules) are required for communication with the

Trunk Time Switch (TTS)
         The TTS has two types of components: the Peripheral Modules (PMs) and
the Common Controls (CCs).

         The PM contains the printed circuit boards that provide the link
between the end office's ANI trunks and the ARC and between the ONI trunks and
the ACD.  The activity of the PM is under direction of the CC

         A PM rack contains five types of circuit boards: Multi-frequency
Receivers (MFRs), Analog Line Front Ends (ALFEs), T1 Front Ends (T1FEs),
Peripheral Module Access Controllers (PMACs), and Multi-purpose Peripheral
Devices (MPPDs).

         The MFRs translate the intercepted number from multi-frequency tones
to ASCII digits for ANI calls; for ONI calls that come through a trunk
concentrator, the MFRs translate the tones sent by the concentrator to
indicate an ONI call.  Based on the tones, the MFR determines the type of
call: regular, trouble, etc.

         ALFEs convert incoming analog data to digital form so that it can be
switched on the digital network.  They also convert outgoing digital data back
to analog.  Incoming ALFEs provide the link between the TTS and the analog
trunks from the Class 5 End Offices.  Outgoing ALFEs provide the link between
the TTS and the analog trunks to the ACD.
         ALFE is subdivided into two types for both incoming and outgoing:
ALFE-A (contains the control logic, PCM bus termination, and ports for 8
trunks) and ALFE-B (contains ports for 16 trunks, but must be paired with an
ALFE-A in order to use the control logic and PCM bus on the backplane).
ALFE-As can be used without ALFE-Bs, but not vice versa.
         Incoming ALFEs support E&M 2-wire, E&M 4-wire, reverse battery, and
3-way signalling trunks.  Outgoing ALFEs support E&M 2-wire, reverse battery,
and high-low trunking.

         T1FEs provide the links between the TTS and the D3-type T1 spans from
the end offices.  They also link the DARU VOCAL board ports and the TTS.  Each
board has 24 ports in order to handle a single T1 span which carries 24 voice

         PMAC is based on a Motorola 68000 microprocessor that directs and
coordinates data flow within the PM.

         MPPD boards provide bus termination and the system clocks for the
digital network.  The MPPD contains a master and a secondary clock, which are
synchronized with the frequency of an incoming T-1 span.  The module also
contains its own clock for use when T-1 synchronization is not available or
         The MPPD also generates the ringing tones, busy signals, and reorder
tones heard by the customer and sends the zip (alert) tone to the operator.

         The CC controls the interaction between the PM components and the
DARU.  It contains the Office Dependent Data Base (ODDB), which is a system
table that describes the configuration of the TTS.  The CC uses the ODDB to
determine whether an incoming call is an ANI or ONI trunk.
         The CC sets up paths through the digital network in order to
coordinate the resources of the CAIS/LAIS.  It receives messages from the
PMAC, stores information necessary for returning a response to the appropriate
trunk, and controls message routing to and from the ARC or the operator.  It
also synchronizes the TTS and the Directory Assistance System (DAS) for
operator-caller communications.
         The CC is a Power-series standalone processor that contains a central
processing unit (CPU-2), based on the Motorola 68000 microprocessor.  The
processor also contains distributed intelligence for controlling the memory
subsystem, the IO (input/output) subsystem, and the disk/tape subsystem.  Each
CC includes a Winchester disk drive, a quarter-inch tape drive, and additional
miscellaneous hardware.

DAIS II Audio Response Unit (DARU)
         The DARU contains the VOCAL boards that produce automated
announcements, which are compiled from a vocabulary stored in RAM.  A
CAIS/LAIS contains 1 to 3 DARUs, each with 48 ports.
         If a CAIS/LAIS houses more than one DARU, the units are multi-dropped
together.  One DARU is always linked to the ARCs (either directly or by modems
and telephone lines) so that the announcement vocabulary can be downloaded
from the ARCs if necessary.


         Much of the information in this file is copied verbatim from the
instructional booklet sent to me by CCI.  Their documentation is extremely
in-depth and well written, and, with some looking over, is easy to
understand. Much of the information in here is confusing with all of the
acronyms used as well as technical terms, but if you cross-reference acronyms
throughout the file, you should be able to see what it stands for.  Also, if
you don't understand what something does, just think of it in terms of use by
the telephone company in the context used and you can generally get an idea
of what it does or is used for.  I hope you enjoyed this file and continue to
read Phrack Inc. files to learn more about the system we use and experience.
Any constructive suggestions are welcomed directly or indirectly.

                                            Taran King

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