Copy Link
Add to Bookmark
Report
Modernz 21
***********************************************************
* *
* *
*^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^*
* Modern Database of Network Terms *
* *
* Alphabetically Listed *
* *
* Part 2 *
*^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^*
* *
* Another Modernz Presentation *
* *
* by *
* Digital-demon *
* *
* (C)opyright December 30,1991 *
***********************************************************
***********************************************************
The Modernz can be contact at:
MATRIX BBS (908)905-6691
The Church of Rodney (908)830-7960
Hellfire BBS (908)495-3926
and any of numerous boards around the country
***********************************************************
Continuation of the databse of network terms.
(I'm too lazy to write anything more at this point in time.)
_-DEMON
**********************************************************
BABT
====
British Approvals Board for Telecommunications.
background process
==================
A scheduled job used for tasks requiring a large amount of processing
time in an ISIS node. The background process is the level at which the
bulk of the processing is done and is given long periods of time at
irregular intervals. Background processes are executed when no
foreground (real time) processes are due to run and can be interrupted
by a foreground task. Also called background job.
Contrast with foreground.
backplane
=========
A printed circuit board with pin connectors on the back to accommodate
buses, jumpers, and/or terminator boards; the front of the board allows
system control boards to be plugged into it. The backplane provides the
means for interboard communication. There are a variety of backplane
architectures; BT North America uses two: BT North America propriety
backplane design (for the Engine family) and the VMEbus (for the
Turbo Engine).
backpressure
============
The process by which data flow (in one direction, on an individual
virtual circuit) is temporarily stopped.
backward channel
================
A channel used for supervisory and/or error control signals transmitted
from the receiving terminal back to the sending device.
Bad Acknowledgment (BAD ACK)
============================
An error condition on a link when a frame has been received with an
invalid ACK field.
bad BORI
========
An error condition on a synchronous line in which the first few bits of
a potential frame do not match any valid BORI. See Beginning-of-Record
Indicator (BORI).
Bad Guy list
============
A list of nodes that are not valid neighbors for a node.
Contrast with Good Guy list.
bad record number
=================
An error condition on a link in which a frame has been received with
an invalid frame (record) number.
ball logic
==========
The use of BT North America-specific, end-to-end messages signaling
specific virtual circuit conditions. This convention of individual
signals can be used if both ends agree on the alternate protocol. The
TYMNET network uses the following ball messages: Black Ball, Glass
Ball, Gray Ball, Green Ball, Orange Ball, Red Ball; each is defined
in this glossary.
band
====
In the electromagnetic spectrum, a frequency range between two defined
limits assigned to a specific purpose. For example, voice-grade
circuits of 300 to 3300 Hertz.
bandwidth
=========
The difference between the highest and lowest frequencies of a band,
expressed in Hertz.
base
====
A type of interface between a host computer and TYMNET data to be fed
directly into the host computer memory through Direct Memory
Access (DMA).
baseline release
================
A TYMNET network software release that contains the latest supported
versions of software and documentation.
BASIC
=====
Beginners' All-purpose Symbolic Interchange Code. A high-level
interactive programming language frequently used with personal
computers and in time-sharing environments.
Basic Bisync Extension-cord Service (BBXS)
==========================================
Now called RJE/HASP Service, this service allows 2780/3780/HASP
devices to remotely access hosts over packet-switching networks.
Can be configured as a TIF or a HIF. Also called Remote Job Entry
(RJE) interface. Although the name of this service has changed, the
product ID remains BBXS.
Basic Rate Interface (BRI)
==========================
An interface to Integrated Services Digital Network (ISDN), used for
individual subscriber terminal equipment. The BRI uses a medium-speed
digital connection of 144 kbps to provide 2 B-channels and 1 D-channel.
The B-channels (bearer channels) operate at 64 kbps and carry voice,
circuit-switched data, and packetized data. The D-channel (signaling
channel) operates at 16 kbps and carries signaling for all B- and
D-channels, and packetized data. See Primary Rate Interface.
Basic Telecommunications
========================
An IBM communication access method that permits Access Method (BTAM)
read/write communications with remote devices.
batch processing
================
A method of processing (on a computer system) that requires similar
input items to be coded and grouped prior to processing.
baud
====
Unit of signaling speed.
baud rate
=========
The rate of speed (number of times) per second a signal is altered.
The number of bits represented by a baud depends on the encoding
technique. If each baud represents one bit condition, the baud rate
equals bits per second (bps).
Baudot
======
A 5-bit, 58-character alphanumeric code originally developed for the
transmission of data on teletype equipment.
BBXS
====
Product ID for RJE/HASP Service (previously called Basic Bisync
Extension-cord Service). This service allows 2780/3780/HASP devices
to remotely access hosts over packet-switching networks. Can be
configured as a TIF or a HIF. Also called Remote Job Entry (RJE)
interface.
BCB
===
Block Control Byte. Transmission control byte to control flow of data
over a link.
BCD
===
Binary Coded Decimal. A code for decimal notation in which the digits
are represented by a 4-digit binary code, in an 8, 4, 2, 1, weighted
notation.
BCS
===
Block Check Sequence. Error detection technique used to determine
whether the block is structured correctly. Two examples are checksum
and Cycle Redundancy Check (CRC).
Beginners' All-purpose Symbolic Interchange Code (BASIC)
========================================================
A high-level interactive programming language frequently used with
personal computers and in time-sharing environments.
Beginning-Of-Record Indicator (BORI)
====================================
A series of synchronization pulses at the beginning of a frame.
A 4-bit open flag of a TYMNET packet.
beta test
=========
An NTD development phase involving testing. These tests are conducted
at customer sites to verify functional soundness of a new or enhanced
product and to ensure that the product performs at an acceptable level.
Also called field trial.
bidirectional
=============
A data bus in which digital information can be transferred in either
direction.
binary
======
A numbering system (radix) using only the digits 0 (off) and 1 (on).
Binary Coded Decimal (BCD)
==========================
A system of representing decimal numbers. Each decimal digit is
represented by four binary digits. For example, in the 8-4-2-1 coded
decimal notation, the number 37 is represented as 0011 0111.
Binary Image Transport System (BITS)
====================================
A program that provides down-line loading and dumping. Used to
transfer files between a UNIX host computer and a target Engine or
Turbo Engine. BITS replaces the Engine LOAD-II, Engine Load Facility
(ELF), and Merge and Link ISIS Nodes (MERLIN) facilities.
Binary Synchronous Communication (BSC)
======================================
A character-oriented protocol developed by IBM, which transmits
binary-coded data synchronously over a link connection. BSC uses a
defined set and sequence of control characters. See Extended Binary
Coded Decimal Interchange Code (EBCDIC).
Binary Synchronous Operations Manager (BOM)
===========================================
A subprocess of the 3270 (IBM) terminal and host interfaces. BOM
allows a user to query and control the polling of 3270-type devices.
It can be accessed through Dynamic Debugging Tool (DDT), or for more
recent versions, a standard login to the BOM host.
bis
===
Used in CCITT Recommendations to mean the second part or addendum.
Used when there is a variation in the definition to meet a specific
purpose. See also ter.
bisync
======
IBM term referring to binary synchronous communication.
bit
===
The smallest unit of information used by the system. A digit in the
binary numbering system. Bit equivalents for the BT North America
Engine processor are as follows:
4 bits = 1 nibble
2 nibbles = 1 byte
8 bits = 1 byte
1 byte = 1 ASCII character
2 bytes = 1 halfword or 16 bits (can convey pictographs such as
Japanese or Chinese characters)
2 half-words= 1 fullword (32 bits)
Bit equivalents for the Turbo Engine processor are as follows:
8 bits = 1 byte
2 bytes = 1 word (16 bits)
4 bytes = 1 longword (32 bits)
bit array
=========
A group of individual bits that describe, to a programmer, a condition
in the program. See flag.
bit-oriented
============
A protocol that can convey control information based on the value and
position of a single bit. This bit pattern represents a flag
character, which separates distinct groups of data bits. Sometimes
referred to as bit-and-position-oriented. Examples of this protocol
are HDLC and SDLC link-level protocols.
BITS
====
Binary Image Transport System. A program that provides down-line
loading and dumping. Used to transfer files between a UNIX host and
computer and a target Engine or Turbo Engine. BITS replaces the Engine
LOAD-II, Engine Load Facility (ELF), and Merge and Link ISIS Nodes
(MERLIN) facilities.
bits per second (bps)
=====================
The basic unit of rate measurement in data communications. The rate at
which bits are represented over an analog or digital communications
path. Bits per second is an information transfer rate, as opposed to
baud, which is a signaling rate.
Black Ball
==========
A message between two nodes indicating data loss. Also called ISIS
Dispatcher message type A4.
block
=====
A group of bits or characters transmitted as a unit. Included in this
group is an encoding procedure for error control purposes.
Block Check Sequence (BCS)
==========================
Error detection technique used to determine whether the block is
structured correctly. Two examples are checksum and Cyclic Redundancy
Check (CRC).
Block Control Byte (BCB)
========================
Transmission control byte to control flow of data over a link.
BND
===
Bound file. A machine-language file generated by MERLIN for an Engine
communications processor containing Kernel code and one or both of the
following: Node Code, NAD Image Binary (NIB) files for interface slots.
board
=====
Printed circuit board.
BOC
===
Bell Operating Company.
BOM
===
Binary Synchronous Operations Manager. A subprocess of the 3270 (IBM)
terminal and host interfaces. BOM allows a user to query and control
the polling of 3270-type devices. It can be accessed through Dynamic
Debugging Tool (DDT), or for more recent versions, a standard login
to the BOM host.
boot
====
A special program (in PROM) that performs loading and dumping
functions.
bootstrap program
=================
A program that enables a node to receive code and to initialize
software.
BORI
====
Beginning-Of-Record Indicator. A series of synchronizatkon pulses
at the beginning of a frame. A 4-bit open flag of a TYMNET packet.
BORI zap
========
The process by which a node forces a link to go down by sending a
reset pattern to the neighbor node.
Boss circuit
============
A virtual circuit from the MUX user's terminal to the ISIS slot
containing the MUX application program. Used to control other
circuits assigned to the user.
bound file (BND)
================
A machine-language file generated by MERLIN for an Engine
communications processor containing Kernel code and one or both of
the following: Node Code, NAD Image Binary (NIB) files for interface
slots.
bps
===
Bits per second.
breakout box
============
Test equipment used to individually separate each RS-232-C, V.24, or
V.35 communications signal for observation.
breakout cable
==============
Various types of I/O cables used for connecting BT North America
hardware products to the network or to other devices.
breakout panel
==============
Hardware used to separate RS-232-C signals into individual signal
port and cables.
breakpoint
==========
A specified point in a program at which the program can be interrupted
by manual intervention or by a control routing. Breakpoints are
generally used as an aid in testing and debugging programs.
BRI
===
Basic Rate Interface. An interface to Integrated Services Digital
Network (ISDN), used for individual subscriber terminal equipment.
The BRI uses a medium-speed digital connection of 144 kbps to provide
2 B-channels and 1 D-channel. The B-channels (bearer channels) operate
at 64 kbps and carry voice, circuit-switched data, and packetized data.
The D-channel (signaling channel) operates at 16 kbps and carries
signaling for all B- and D-channels, and packetized data.
See Primary Rate Interface.
bridge
======
A connected device that permits communications between Local Area
Networks (LANs) supporting similar protocols, which are logically or
physically separated from each other. For example, using ring
topology, two rings can be linked together over a bridge. The bridge
switches the data from one ring to another.
BSC
===
Binary Synchronous Communication. A character-oriented protocol
developed by IBM, which transmits binary-coded data synchronously
over a link connection. BSC uses a defined set and sequence of control
characters.
See Extended Binary Coded Decimal Interchange Code (EBCDIC).
BTAM
====
Basic Telecommunications Access Method. An IBM communication access
method that permits read/write communications with remote devices.
bubble
======
The process by which a TYM2 link acquires additional channels to
accommodate new circuits. This is accomplished by assigning additional
addresses for routing individual circuits across the link. A bubble
expands a link in increments of 128 channels. This method of link-level
traffic management is similar to Statistical Time Division
Multiplexing. Contrast with shrink.
buffer
======
A storage area used to compensate for a difference in data flow rate
when data is transmitted from one device to another. Short-term data
storage.
buffer character count (BCT)
============================
The (approximate) number of bytes currently in each buffer.
buffer pair
===========
A pair of buffers that is associated with each virtual circuit; there
is one buffer for each direction of data flow. The buffer pair ties
together two absolute channels of a virtual circuit.
buffer zap
==========
A traffic condition that forces Node Code to reallocate the memory
buffers of the largest user, due to traffic requirements. This results
in the user losing data and the initiation of a Black Ball message in
the direction of the data loss.
bufferlet
=========
A 16-byte area of memory in Node Code where buffered data is stored
(short term). The 16-byte area of memory contains 14 bytes of data
and a 2-byte pointer to the next bufferlet.
bufferlet pool
==============
A quantity of unassigned, formatted bufferlets.
bus
===
A circuit that connects a number of locations.
byte
====
A group of consecutive binary digits recognized as one unit by a
computer. Normally, a byte has 8 bits equivalent to a single character,
but some computers use 16-bit or 32-bit bytes. See bit. See also word.
***********************************************************
Modernz Forever - MATRIX BBS (908)905-6691
