| adapter |
Another
name for a printed-circuit board or card that fits in a computer's
expansion slot and allows dedicated processing of data. |
| AIB |
Application
Interface Board. A PCM mezzanine card that attaches to an ARTIC
PCI-bus adapter to enable customized communications. |
| API |
Application
Programming Interface. Software designed to make computer
functions available to application programs. |
| ARTIC |
A
Realtime Interface Coprocessor. A line of dedicated real-time
communications cards originally produced by IBM in 1986. |
| asynchronous |
A
common method of transmitting data where each character is
transmitted separately with no time synchronization between
sending and receiving devices. It is cheap and dependable, but
slow. |
| backbone |
A
transmission facility that connects lower-speed distribution
channels or clusters of users and devices. |
| baseband |
Digital
data transmission in which a wire or cable carries only one
signal. In contrast, broadband transmission carries multiple
simultaneous signals. Most PCs use baseband for communicating with
printers, monitors, and modems. |
| bisynchronous |
Binary
Synchronous. Also BSC or bisync. An IBM standard for synchronous
transmission of binary-coded data as a serial stream of binary
digits. |
| broadband |
Digital
data transmission in which a wire or cable carries multiple
simultaneous signals. In contrast, baseband transmission carries
only one signal. |
|
A
collection of wires through which data are transmitted from one
part of a computer to another. |
| bus
width |
Bus
width is a measure of data transmission speed on computer buses.
Typical widths are 8, 16, 32, or 64 bits at a time. |
| channel |
The
communication path between two computers of devices. It can refer
to the physical medium (such as coaxial cables), or to a set of
properties that differentiate channels. |
| CCITT |
Comite
Consultatif International Telegraphique et Telephonique. A
communications standards agency of the United Nations that was
reorganized in 1993 to become the International Telecommunications
Union (ITU). |
| co-processor |
An
intelligent adapter that has its own on-card processor to share
the processing load with the host computer's CPU. |
| communications |
The
transmission of data from one computer (or device) to another. |
| Compact
PCI |
Compact
PCI is electrically a superset of PCI with a different physical
form factor. CompactPCI utilizes the Eurocard form factor
popularized by the VME bus, designated as 3U or 6U card size. |
| CSU/DSU |
Channel
Service Unit / Data Service Unit. The two units are usually
packaged together. The CSU connects a terminal to a digital
telecommunications line; the DSU performs protective and
diagnostic functions for the line. The same brand of CSU/DSU is
requir |
| DCE |
Data
Circuit Terminating Equipment. Sets up and maintains a data
connection link over a communications medium. For example, a
modem. |
| DTE |
Data
Terminal Equipment. The part of a data station that serves as a
data source, destination, or both and that provides for the data
communications control function according to protocols. This will
be used to describe a router or similar device. |
| duplex |
Simultaneous
transmission in both directions, sometimes referred to as full
duplex to differentiate it from half duplex, which alternates
transmission in one direction, then in the other. |
| E1 |
A
European dedicated phone connection that supports a data rate of
2.048 Mbps. An E1 line consists of 32 channels, each of which
supports a rate of 64 Kbps. |
| EIA |
Electronics
Industries Association. A United States electronics trade
organization that concentrates on hardware interface standards. |
| EIB |
Electrical
Interface Board. A smaller card that attaches to an ARTIC adapter
and determines the number of ports and physical electrical
standard the signals will adhere to. |
| expansion
bus |
This
is a PC computer bus that allows expansion cards (such as
communications cards) to access the computer's CPU and memory. The
bus width determines how many bits of data can be transmitted at
once; typical widths are 8, 16, 32, or 64. The bus clock spe |
| Fractional
T1 |
One
of the 24 channels that comprise a full T1 data line. Fractional
T1 lines can usually be leased individually. |
| frame
relay |
Frame
relay is a high-speed packet-switching protocol used in wide area
networks. It uses variable-length frames. Frame relay is faster
than earlier protocols because it omits flow control and error
correction. It provides service up to T1 (or DS1) rates of 1.544
Mbps. |
| full
duplex |
A
communications system or channel capable of simultaneous
transmission in two directions. Same as "duplex." |
| half
duplex |
A
communications channel allowing alternating transmission in two
directions, but not in both directions simultaneously. |
| HDLC |
High
level Data Link Control. An ISO-standard set of protocols for
transmitting data with error detection and flow control. Similar
to IBM's SDLC. |
| IP |
Internet
Protocol. The IP part of the TCP/IP protocol routes a message
across networks. |
| ISA |
Industry
Standard Architecture. This computer architecture, developed by
IBM, allows 16 bits of data at a time to flow between the
motherboard circuitry and adapters on the ISA bus. |
| ITU |
International
Telecommunications Union. New name in 1993 for the former CCITT.
They produce technical recommendations for radio, telegraph,
telephone and data communication interfaces that become
international standards. The ITU-T sector deals with
telecommunications, and the standards they produce are prefaced
with an ITU-TS identifier. |
| Kbps |
Abbreviation
for a data transmission speed of kilobits per second, usually
considered to be 1024 bits/second. |
| LAN |
Local
Area Network. A LAN is a group of computer devices (such as PCs,
workstations, printers and storage devices) connected in a network
in close proximity to each other. For example, a LAN might connect
all computers within one building. |
| LAP-B |
Link
Access Protocol B. A link set-up routine to establish and maintain
computer links. |
| leased
line |
A
phone line that is rented for exclusive use from one location to
another. |
| Mbps |
Abbreviation
for a data transmission speed of megabits per second, usually
considered to be 1,048,576 bits/second. |
| MCA |
Micro
Channel Architecture. Developed by IBM for its desktop computers,
MCA was an improvement, but Its proprietary nature discouraged
other manufacturers, and IBM has dropped it from their systems. |
| Micro
Channel |
Micro
Channel Architecture (MCA). Developed by IBM for its desktop
computers, MCA was an improvement, but Its proprietary nature
discouraged other manufacturers, and IBM has dropped it from their
systems. |
| modem |
Modulator-Demodulator.
An electronic device that allows computers to communicate over
ordinary telephone lines. It transforms digital computer signals
into analog signals that are then transmitted over phone lines to
another modem that reconstructs the di |
| modem
eliminator |
A
device that replaces a modem when the distances are short. It take
power from the transmission line. |
| multiplexing |
An
electronic or optical process that combines a large number of
lower-speed transmission lines into one high-speed line, thereby
concentrating traffic and improving efficiency. |
| packet |
A
group of binary digits that are grouped, uniquely labeled, and
transmitted together. |
| packet
switching |
A
digital technique whereby messages are divided into packets before
they are sent, and reassembled correctly once they reach their
destination. Each packet contains message data and code that
describes the origin, final destination, and packet order for |
| PCI |
Peripheral
Component Interconnect. PCI is a bus standard developed by Intel
Corporation for PCs. PCI is a 64-bit bus, but can be implemented
as a 32-bit bus; it can run at speeds of 33 MHz or 66 MHz. |
| PMC |
PCI
Mezzanine Card. The PMC is a small card that plugs into a PCI
card, that them plugs into the computer bus as a unit. |
| port |
A
communication point of access where information goes into and/or
out of a computer. |
| PPP |
Point
to Point Protocol. A communications protocol that allows a
computer to use a regular telephone line and a modem to make
connections. Best known for TCP/IP connection to the Internet. |
| protocol |
An
agreed-upon set of rules or format for transmitting data between
two computer devices. A protocol will always include data, and may
also define methods for error-checking, data-compression,
end-of-message notice, and receipt-of-message notice. |
| PSTN |
Public
Switched Telephone Network. This is the familiar telephone service
based on copper wire that carries analog voice data. It is also
called POTS (Plain Old Telephone Service). |
| RCM |
Realtime
Control Microcode. This is the ARTIC-specific, multitasking
operating system that manages the ARTIC processor tasks and
resources. |
| real
time |
A
transmission or data processing mode in which the data is entered
in an interactive session where an application can respond fast
enough to affect later data input. |
| router |
A
special-purpose computer or software package that handles the
connection between two or more networks. A router handles packets
by looking at their destination addresses and accordingly sending
them via a given route. |
| RS-232 |
A
TIA/EIA standard, also called EIA-232. A common serial
communication electrical standard used by computers with data
rates up to 20 Kbps. It is suitable for both synchronous and
asynchronous communications. |
| RS-422 |
A
TIA/EIA standard, also called EIA-422. This is a balanced
implementation of EIA-449 for high speed data transmission. RS-422
can use either a 37-pin connector defined by RS-449, or a 25-pin
connector defined by RS-530. |
| RS-449 |
A
TIA/EIA standard, also called EIA-449. This 37-pin standard
supports data transmission up to 2 Mbps. Each signal line has its
own return line instead of a common ground return. |
| RS-485 |
A
TIA/EIA standard, also called EIA-485. |
| SDLC |
Synchronous
Data Link Control. An IBM standard protocol used in their SNA
systems. Can be used with full or half duplex lines. |
| SS7 |
Signaling
System 7. SS7 is an international telecommunications protocol
standard for transmitting digital data on a broadband network. |
| switch |
A
device that opens or closes circuits or selects the path or
circuits to be used for transmission of information. |
| synchronous |
Data
transmission at a fixed rate. It eliminates the need for start and
stop bits that asynchronous transmission requires. The receiver
and transmitter must be synchronized to work at the same rate. |
| T1 |
A
North American dedicated phone connection that supports an
aggregate data rate of 1.544 Mbps. A T1 line consists of 24
channels, each of which supports a rate of 64 Kbps and can often
be individually leased as "fractional T1" lines. Also
called DS1 lines. |
| TCP |
The
TCP part of the TCP/IP protocol suite provides transport protocol
rules which ensure that the data sent is received correctly at the
other end. |
| TCP/IP |
Transmission
Control Protocol/Internet Program. A suite of protocols that
enables linking of dissimilar computers to access the Internet or
another network. |
| throughput |
The
amount of data transferred from one place to another. Throughput
is typically expressed in Kbps or Mbps. |
| V.35 |
A
CCITT electrical standard. It specifies 34-pin connections and
data transmissions at 48 Kbps, although it is frequently used for
data rates up to 64 Kbps. |
| WAN |
Wide
Area Network. A WAN is a group of distant computer systems
connected in a network. For example, a WAN might connect bank
computers in the 10 largest cities in Australia. |
| X.21 |
A
synchronous signaling interface specified by CCITT (now the ITU).
It has error checking and supports data transfer to 64 Kbps. |
| X.25 |
A
CCITT (now the ITU) standard for interfacing over a
packet-switched data network. |