name for a printed-circuit board or card that fits in a computer's
expansion slot and allows dedicated processing of data.
Interface Board. A PCM mezzanine card that attaches to an ARTIC
PCI-bus adapter to enable customized communications.
Programming Interface. Software designed to make computer functions
available to application programs.
Realtime Interface Coprocessor. A line of dedicated real-time
communications cards originally produced by IBM in 1986.
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.
transmission facility that connects lower-speed distribution
channels or clusters of users and devices.
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.
Synchronous. Also BSC or bisync. An IBM standard for synchronous
transmission of binary-coded data as a serial stream of binary
data transmission in which a wire or cable carries multiple simultaneous
signals. In contrast, baseband transmission carries only one
collection of wires through which data are transmitted from one
part of a computer to another.
width is a measure of data transmission speed on computer buses.
Typical widths are 8, 16, 32, or 64 bits at a time.
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.
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).
intelligent adapter that has its own on-card processor to share
the processing load with the host computer's CPU.
transmission of data from one computer (or device) to another.
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.
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
Circuit Terminating Equipment. Sets up and maintains a data connection
link over a communications medium. For example, a modem.
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.
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.
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.
Industries Association. A United States electronics trade organization
that concentrates on hardware interface standards.
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.
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
of the 24 channels that comprise a full T1 data line. Fractional
T1 lines can usually be leased individually.
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.
communications system or channel capable of simultaneous transmission
in two directions. Same as "duplex."
communications channel allowing alternating transmission in two
directions, but not in both directions simultaneously.
level Data Link Control. An ISO-standard set of protocols for
transmitting data with error detection and flow control. Similar
to IBM's SDLC.
Protocol. The IP part of the TCP/IP protocol routes a message
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.
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.
for a data transmission speed of kilobits per second, usually
considered to be 1024 bits/second.
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.
Access Protocol B. A link set-up routine to establish and maintain
phone line that is rented for exclusive use from one location
for a data transmission speed of megabits per second, usually
considered to be 1,048,576 bits/second.
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.
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
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
device that replaces a modem when the distances are short. It
take power from the transmission line.
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.
group of binary digits that are grouped, uniquely labeled, and
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
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.
Mezzanine Card. The PMC is a small card that plugs into a PCI
card, that them plugs into the computer bus as a unit.
communication point of access where information goes into and/or
out of a computer.
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.
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.
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).
Control Microcode. This is the ARTIC-specific, multitasking operating
system that manages the ARTIC processor tasks and resources.
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.
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.
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.
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
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.
TIA/EIA standard, also called EIA-485.
Data Link Control. An IBM standard protocol used in their SNA
systems. Can be used with full or half duplex lines.
System 7. SS7 is an international telecommunications protocol
standard for transmitting digital data on a broadband network.
device that opens or closes circuits or selects the path or circuits
to be used for transmission of information.
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.
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 part of the TCP/IP protocol suite provides transport protocol
rules which ensure that the data sent is received correctly at
the other end.
Control Protocol/Internet Program. A suite of protocols that
enables linking of dissimilar computers to access the Internet
or another network.
amount of data transferred from one place to another. Throughput
is typically expressed in Kbps or Mbps.
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.
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.
synchronous signaling interface specified by CCITT (now the ITU).
It has error checking and supports data transfer to 64 Kbps.
CCITT (now the ITU) standard for interfacing over a packet-switched