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- 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.
- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
-
-
-
- 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.........
-
- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
-
-
-
-
- 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.
-
- Downloaded From P-80 Systems 304-744-2253
-