WARNING........ 
 
 THE FOLLOWING FILE IS NOT FOR THE NOVICE IN PHREAKING.  YA WANT TO KNOW HOW 
TO GET YERSELF LD CODES, GO BOTHER YER LOCAL HACK/PHREAK BOARD FOR THAT. 
 
NOW THEN........ 
 
 
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<->                                                                        <-> 
<->                         The Phreaker's Guide to                        <-> 
<->                       ESS1 & 1A Switching Systems                      <-> 
<->                                                                        <-> 
<->                       Researched and Compiled by                       <-> 
<->                          -=+NINJA MASTER+=-                            <-> 
<->                                                                        <-> 
<->                                5/10/87                                 <-> 
<->                                _______                                 <-> 
<->                               |File #1|                                <-> 
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<->            "Forever Servicing The Phreak/Hack Community"               <-> 
<-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-><-> 
 
 
 Hello, and welcome to the first in a continuing series on the ESS1 and 1A  
switching systems.  The information in this series had been obtained from my 
knowledge and by trashing various empire (AT&T,BELL) trash binns. 
 
In this first file I will start off with a very basic review of what the 
ESS system is, and will then go on to talk about some other things you 
will find interesting. 
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The ESS System In Review 
------------------------ 
 
ESS (Which stands for Electronic Switching System) was designed by good old 
AT&T in the state of the art labs of the computer-controlled space-division.
The principle is simple, you have a switching system that is controlled by
simple electronics and stored computer programs. (not to be confused with
CCIS which is just a interoffice command link). 
 
The ESS system is a class 5(End Office) system, and has some spinoffs (like 
the  No. 10A RSS [Remote Switching System]).  It uses digital transmissions,
although they must be converted to analog by a hybrid as this is what kind of
electronics AT&T chose to use. 
 
The ESS is divided in to seperate modules, so as to make repairs and additions 
easier.  Each module is connected to the system by interfaces (one of which 
will be covered later).  In a whole, the ESS system provides the standard
BORSCHT functions, plus some extra ones. 
 
Well, them there's the basics, now on with the good, technical, informational, 
 
fun stuff......... 
 
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 ESS1A Procesor 
 -------------- 
 
  The follwing is about the 1A Processor, and will give you an understanding 
on how it functions. 
 
  The 1A processor is used for a number of ESS systems, but most specifically 
is used for the following: 
  
 o   To control the 4 ESS switch. 
 
 o   To control the 1A ESS switch. 
 
 o   To be added to older 1 ESS switches, so as to update it to a 1A ESS. 
 
 o   To support future switching systems. 
 
 o   To accommodate bulk memory systems. 
 
 o   And to provide real time and continuous control through highly automatic 
     maintenance. (less than 2 hours downtime in 40 years continuous operation). 
 
 The 1A processor uses stored programs, and operates in a real time environment. 
The processor can function without being hooked up to the switching network. 
The processor is devoted to internal maintenance and administrative tasks.  So 
TELCO employe's can monitor the processor (from now on called the 1A) it is  
hooked up to control panels and to I/O terminals.  (which, incidentally  
interface with software defined I/O channels). 
 
 All frames (they make up the 1A) sent out from the 1A are duplicated. 
So that a failure from one won't screw up and equipment. 
 
 The following is a high level block diagram of the 1A: 
 
 _________ 
|Attached | 
|Processor|_________ 
|System   |        | 
 ---------         | 
                   | 
                   |                                      ___________ 
 ___________       |                                     |           | 
|           |      ^                                     | Auxiliary | 
| File Store|----< <-------------------*-----------------| Data      | 
|           |                          |                 | System    | 
 -----------                           |                 |           | 
                                       |                  ----------- 
                                       | 
                                       | 
                                       | AU BUS  
                                       | 
                                       | 
 ___________                 __________|_________               ____________ 
|           |               |                    |             |            | 
| Program   |   PS Bus      |      Central       |   CS Bus    | Call Store | 
| Store     |---------------|      Control       |-------------|            | 
|           |               |                    |              ------------ 
 -----------                 ----------|---------               
                                       | 
                                       | PU Bus      ___________   Data and 
                                       |            |           |  control 
                                       *------------|  I/O      |------------- 
                                       |            | Interface |   to/from 
                                       |            |           |    I/O  
                                       |             -----------   terminals 
                                       |                  |            
                                       |                  | 
                                       |                  |E2A Telemetry 
                                       | PU Bus           |Control 
                                       |                  | 
               Status                  |                  | 
 _________     And             ________|_______           | 
|         |    Control        |                |<----------    Pu Bus To/From 
| Control |-------------------| Periphel       |--------------------------using 
| Panels  |                   | System         |                       system
|         |                   | Interface      |                     peripheal 
 ---------                    |                |                               
                              |                |  E2A Telemetry Control Inhibit 
to No. 2    Telemetry Data    |                |<----------------------\ 
SCCS        And Control       |                |                        | From 
Maintenance-------------------|                |<--Office--Alarms-------|Using 
Facility                      |                |                        |System 
                              |                |<--Building--Alarms----/ 
                              |                | 
                               ---------------- 
 
         LEGEND 
         ------ 
  AU--Auxiliary Unit 
  CS--Call Store 
  PS--Program Store 
  PU--Peripheral Unit 
SCCS--Switching Control Center System 
 
About the above: 
 
Central Control: Interfaces with the 1A, and performs the processing functions 
     of the 1A.  It also executes all maintenance routines. 
 
Program Store: High speed semiconductor that stores program instructions, and  
     system configuration system. 
 
Call Store: Similar to the above, but is used for storage translation data, 
and frequently changed call processing data, such as: 
  
       o  Status of trunks and switching network. 
 
       o  Records of network terminations used for each call in progress. 
 
       o  Digits received and digits to be outpulsed. 
 
       o  Maintenance data related to programmed diagnostic tests. 
 
     Call store also includes an emergency system recovery program, used to  
     establish a working system of a program store failure. 
 
File Store:  Magnetic disk memory, used for program backup. 
 
Attached Processor System: 3B20D computer, of which one or more are used as  
      slave processors (used for multitasking, ect.) 
 
Auxillary Data System:  Magnetic tape system used to store and retrieve data 
      such as system reinitialization, memory dumps, ect...... 
 
I/O interface:  Used to connect 1A to terminals used to input control mesages, 
      and to recieve status messages. 
 
Peripheral System Interface:  Serves as the main junction between all 
peripherals. 
 
Control Panels:  An additional I/O device used to monitor the 1A, and to  
      exercise manual control over the 1A. 
  
         (Yes, this is the big computer you've all seen before, 
               compleat with blinking lights, and little switches) 
 
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 Well, that's it for this file.  If anyone wants more detailed info such as  
system schematics, address spectrums, ect...  then leave me mail on any of the 
boards listed at the end of this file. 
 
 
*Next file:  Mobile Bandits (Those good old mobile switching systems).* 
 
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Any comments, questions, ect....  you can reach me on the following boards: 
 
 
Ripco         Crowley Manor      Phreak Klass 2600 
 
Skidds Lab    Music Playground   Pandemonium 
 
 
 
[*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*] 
[*]                   A /\/\aster \/\/orks II Presentation                 [*] 
[*]                              Copyright 1987                            [*] 
[*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*][*] 
