Multitech ProxyServer MTPSR3-100, User Manual

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MTPSR3-100 User Guide

A

Access: The T1 line element made up of two pairs of wire that
the telephone company brings to the customer premises. The
Access portion ends with a connection at the local telco (LEC or
RBOC).

Accunet Spectrum of Digital Services (ASDS): The AT&T 56K
bps leased (private) line service. Similar to services of MCI and
Sprint. ASDS is available in nx56/64K bps, where n=1, 2, 4, 6, 8,
12.

ACK (ACKnowledgement code) (pronounced “ack”): A
communications code sent from a receiving modem to a
transmitting modem to indicate that it is ready to accept data. It
is also used to acknowledge the error-free receipt of transmitted
data. Contrast with NAK.

Adaptive Differential Pulse Code (ADCPM): In multimedia
applications, a technique in which pulse code modulation
samples are compressed before they are stored on a disk.
ADCPM, an extension of the PCM format, is a standard encoding
format for storing audio information in a digital format. It reduced
storage requirements by storing differences between successive
digital samples rather than full values.

Address: A numbered location inside a computer. It’s how the
computer accesses its resources, like a video card, serial ports,
memory, etc.

AMI line coding: One of two common methods of T1 line coding
(with B8ZS). AMI line coding places restrictions on user data
(B8ZS does not).

Analog signal: A waveform which has amplitude, frequency and
phase, and which takes on a range of values between its
maximum and minimum points.

Analog Transmission: One of two types of telecommunications
which uses an analog signal as a carrier of voice, data, video,
etc. An analog signal becomes a carrier when it is modulated by
altering its phase, amplitude and frequency to correspond with
the source signal. Compare with digital transmission.

Application Program Interface (API): A software module
created to allow dissimilar, or incompatible applications programs
to transfer information over a communications link. APIs may be
simple or complex; they are commonly required to link PC
applications with mainframe programs.

ASCII (American Standard Code for Information Interchange)
(pronounced “askey”): A binary code for data that is used in
communications and in many computers and terminals. The code
is used to represent numbers, letters, punctuation and control
characters. The basic ASCII code is a 7-bit character set which
defines 128 possible characters. The extended ASCII file
provides 255 characters.

Asynchronous Transfer Mode (ATM): A very high-speed
method of transmission that uses fixed-size cells of 53 bytes to
transfer information over fiber; also known as cell relay.

AT Commands: A standard set of commands used to configure
various modem parameters, establish connections and
disconnect. The “AT” is used to get the “attention” of the modem
before the actual command is issued.

Availability: The measure of the time during which a circuit is
ready for use; the complement of circuit “outage” (100% minus %
outage = % available).

B

B7ZS (Bipolar 7 Zero Suppression) line coding: One method
of T1 line coding (see also “B8ZS” and “AMI”). B7ZS line coding
does not place restrictions on user data (AMI does).

B8ZS (Bipolar 8 Zero Suppression) line coding: One of two
common methods of T1 line coding (with AMI). B8ZS line coding
does not place restrictions on user data (AMI does). A coding
method used to produce 64K bps “clear” transmission. (See also
“B7ZS” and “AMI” line coding)

Backbone: 1. A set of nodes and their interconnecting links
providing the primary data path across a network. 2. In a local
area network multiple-bridge ring configuration, a high-speed link
to which the rings are connected by means of bridges. A
backbone may be configured as a bus or as a ring. 3. In a wide
area network, a high-speed link to which nodes or data switching
exchanges (DSEs) are connected. 4. A common distribution core
that provides all electrical power, gases, chemicals, and other
services to the sectors of an automated wafer processing
system.

Background: An activity that takes place in the PC while you are
running another application. In other words, the active user
interface does not correspond to the ‘background’ task.

Bandwidth: The transmission capacity of a computer channel,
communications line or bus. It is expressed in cycles per second
(hertz), the bandwidth being the difference between the lowest
and highest frequencies transmitted. The range of usable
frequencies that a transmission medium will pass without
unacceptable attenuation or distortion. Bandwidth is a factor in
determining the amount of information and the speed at which a
medium can transmit data or other information.

Backward Explicit Congestion Notification (BECN): A bit that
tells you that a certain frame on a particular logical connection
has encountered heavy traffic. The bit provides notification that
congestion-avoidance procedures should be initiated in the
opposite direction of the received frame. See also FECN
(Forward Explicit Congestion Notification).

Basic Rate Interface (BRI): An ISDN access interface type
comprised of two B-channels each at 64K bps and one D-
channel at 64K bps (2B+D).

Bell Operating Companies (BOC): The family of corporations
created during the divestiture of AT&T. BOCs are independent
companies which service a specific region of the US. Also called
Regional Bell Operating Companies (RBOCs).

Bell Pub 41450: The Bell publication defining requirements for
data format conversion, line conditioning, and termination for
direct DDS connection.

Bell Pub 62310: The Bell publication defining requirements for
data format conversion, line conditioning, and termination for
direct DDS connection.

Binary Synchronous Communication (BSC): A form of
telecommunication line control that uses a standard set of
transmission control characters and control character sequences,
for binary synchronous transmission of binary-coded data
between stations.

Bit (Binary digIT): A bit is the basis of the binary number
system. It can take the value of 1 or 0. Bits are generally
recognized as the electrical charge generated or stored by a
computer that represent some portion of usable information.