DACS Digital Access Cross-connect System.
A device that enables organizations to link local
voice, data, and video circuits to high-speed wide area networks.
Dedicated line A communications
channel leased from a telecommunications company by a customer
for its exclusive use 24 hours a day. Most dedicated lines are
used for transmitting large volumes of voice and/or data traffic.
Same as leased line or private line.
Dial-up connection A temporary,
as opposed to dedicated, connection between two computers established
through a standard telephone line.
DSU/CSU Data Service Unit/Channel Service Unit.
A data communications device that converts digital signals received
from a router so that they can be transmitted through leased lines,
and vice versa.
E-mail Electronic mail.
A set of software programs that enable computer users to exchange
messages and files with other computer users through digital communication
networks, including the Internet. Most e-mail messages contain
only text, but graphics, picture, sound, and even video files
can be attached.
E-mail address A two-part
address that identifies the destination of an e-mail message.
The first part of the address identifies a person or mailbox,
while the second usually identifies an organization (for example,
governor@state.sc.us)
E-mail discussion list
An on-line forum that allows network users to easily send messages
to everyone who has subscribed to a particular list. There are
of thousands of e-mail discussion lists (sometimes called "listservs")
on the Internet, and they deal with almost every subject imaginable.
Fractional T1 line A communications
channel that is greater than 56 or 64 kbps but less than 1.544
kbps. For example, one-sixth (256 kbps), one-fourth (384 kbps),
and one-half (768 kbps) of a T1.
Frame Relay Service A
connectionoriented data transport service that enables organizations
to connect LANs through the public telephone network. Frame Relay
is best suited for "bursty" LAN-to-LAN traffic in many-to-one
wide area networks. Because Frame Relay requires pre-defined
data paths ("virtual circuits) between every pair of network
locations, its costs increase significantly for any-to-any (full-mesh)
networks. Frame Relay can be used for voice and video transmissions,
but it is used primarily for data traffic.
Gopher A type of on-line
public information delivery system that enables people to find
text documents by selecting choices from hierarchial menus. For
example, to learn more about pecan trees, you might choose plants
from a Gopher's main menu, then trees from the plants submenu,
then pecan from the trees submenu- at which point the text
of a Clemson University pamphlet entitled "Growing Pecans
in South Carolina" might appear on your computer screen.
While a Gopher's main menu is located on a single computer, its
submenus and the information you find at the end of a menu path
can be located anywhere on the Internet.
Gophers are easy to use and easy to maintain, but
their popularity has declined since the advent of graphical World-Wide
Web sites.
Host A computer that enables
its users to communicate with other host computers on a network.
Individual users communicate by using application programs such
as electronic mail, Telnet, and FTP.
Info Avenue Info Avenue Internet Services.
South Carolina's only state-based, statewide Internet access
provider. The State of South Carolina has contracted with Info
Avenue to provide Internet access for state and local government
agencies through August 1998.
Independent telephone company
A local telephone company that is not a Bell regional company
operating company. In South Carolina this includes every local
telephone carrier except BellSouth-a total of 26 companies.
Internet The world's largest
collection of interconnected computer networks. The Internet
consists of tens of thousands of local, regional, and national
networks that are linked together by specialized computers called
routers. These routers enable these diverse networks to function
as though they were a single network.
Internet access provider
A local, state, regional, or national company that connects individuals
and/or businesses and other organizations to the Internet. Most
individuals and small businesses use modems and ordinary telephone
lines to connect to Internet access providers. Larger organizations
typically use leased 56 KB or T1 lines. More than 60 internet
access providers currently serve locations within South Carolina.
Internet presence provider See
Web hosting service.
ISP Internet service provider.
A company that provides Internet access, hosts World-Wide
Web sites, or develops Web sites. Many ISPs provide all three
of these services.
InterLATA carrier A company
that is authorized to provide telecommunication services that
originate in one LATA and terminate in another. Examples: AT&T,
iSCAN, MCI, SCANA, SCNet, and Sprint.
InterLATA line A communication
circuit that originates in one LATA and terminates in another.
These lines can be leased only from interLATA carriers.
IP Internet Protocol.
The network layer for the TCP/IP protocol suite on which the
Internet is based. IP is a connectionless, best-effort packet-switching
protocol.
iSCAN A recently formed
South Carolina-based company that is owned by 22 independent telephone
companies and SCNet. iSCAN is installing ATM switches throughout
the state, and its goal is to become the number one provider of
broadband communications services in South Carolina.
ISDN Integrated Services Digital Network.
A transmission protocol for carrying voice, data, facsimile,
and video signals across an ordinary residential or business telephone
line. ISDN requires a special modem.
kbps Kilobits per second.
Thousands of bits per second; a standard unit of measure for
transmission speeds over digital lines.
LAN Local Area Network.
A network that serves a restricted area such as a building or
campus.
LATA Local Access and Transport Area.
Geographic boundaries that define the area within which local
telephone companies can provide customer services such as local
calling and private lines. South Carolina has four major LATAs
(Charleston, Columbia, Florence, and Greenville) and three cross-boundary
LATAs (Augusta-Aiken, Charlotte-Rock Hill, and Savannah-Hilton
Head).
Leased line See dedicated
line.
MAN Metropolitan Area Network.
Up to 80 kilometers
mbps Megabits per second.
Millions of bits per second; a standard unit of measure for transmission
speeds over high-speed digital lines.
MidNet A community information
network that serves the Columbia area and is supported by the
Richland County Library, SCETV, and the University of South Carolina.
Modem Modulator-demodulator.
A relatively slow data communications device that converts digital
signals to analog signals, and vice versa. Individuals and smaller
organizations typically use modems to access remote computers
through ordinary telephone lines.
Network information Any
information that is provided through a network, especially the
Internet.
Node Any device that is
connected to a computer network and sends and receives data transmissions;
includes personal computers, workstations, network computers,
servers, and routers.
NTIA National Telecommunications and Information
Administration. A division of the U.S.
Department of Commerce.
OIR Office of Information Resources.
An operational arm of the South Carolina State Budget and Control
Board that is responsible for communications infrastructure planning
and the provision of telecommunications, microwave, data processing,
network management, and printing services to state government
agencies.
On-line Connected to or
available through a computer network.
Packet A generic term
for a unit of data (message) sent across a network.
PPP Point-to-Point Protocol.
A network protocol for transmitting packets over serial pointtopoint
links such as telephone lines. PPP is typically used to connect
home and business computers to Internet access providers through
dial-up modems.
Private line See dedicated
line.
Proprietary Owned and
controlled by a particular company; not open or shared; not in
the public domain.
Response time The time
period between the transmission of an interactive command to a
computer and the reception of a response.
Router A specialized computer
used to connect computer networks and network segments (branches).
Routers make decisions about what paths network traffic should
travel to reach its destination. Many organizations use routers
as the central hub of their local area networks, and all organizations
must use a router to connect to the Internet. Most of the routers
used by South Carolina government agencies, schools, and colleges
are made by a California company called Cisco Systems.
SCINET South Carolina Information Network.
A collection of computer, telephone, and video networks operated
by the State Budget and Control Board's Office of Information
Resources (OIR). SCINET includes a Columbia metropolitan area
network called MetroNet as well as five statewide networks-three
computer networks, one combination computer and long-distance
telephone network, and one video network.
SCIway Web A World-Wide
Web site that is a subject-oriented directory of information about
South Carolina on the Internet. SCIway Web (http://www.sciway.net)
is hosted and supported by The Citadel as a public service.
SCNet South Carolina Net, Inc.
A South Carolina-based company that provides interLATA communications
services. The State of South Carolina has contracted with SCNet
to provide interLATA leased lines for state and local government
agencies until at least January 1998.
Server A computer that
supplies shared resources (such as files and printers) to other
network computers
Shared line A communication
circuit that is used by more than one organization at the same
time. Normally the various organizations using a shared line
pay a portion of its cost.
SMDS Switched Multimegabit Data Service.
A connectionless, cellswitched data transport protocol
that enables organizations to interconnect LANs and WANs through
the public telephone network. SMDS switches read the addresses
of individual data cells (fixed-sized packets) and forward them
to the correct destination over the least congested routes in
the SMDS network. Because SMDS does not require pre-defined network
paths between sites, it is ideally suited for any-to-any (full-mesh)
networks in which each site needs to be able to communicate with
all other sites.
Connecting a LAN to an SMDS backbone network requires
a router and an SMDS-compatible DSU/CSU. SMDS supports several
network protocols, including TCP/IP, Novell's IPX, AppleTalk,
DECnet, SNA, and OSI; but it does not support voice and video
transmissions. In South Carolina SMDS is provided by BellSouth
(see CDS) and some independent local telephone companies.
SMTP Simple Mail Transfer Protocol.
The TCP/IP protocol governing electronic mail transmissions.
SNA Systems Network Architecture.
A proprietary networking architecture used by IBM and IBM-compatible
mainframe computers.
SONET Synchronous Optical Network.
An international standard, fiberoptic transmission concept
for broadband transport. SONET offers a variety of optical line
rates, all of which are multiples of 51.840 mbps. It provides
users with the ability to send signals at multigigabit rates over
singlemode fiber optic cabling.
T1 line A digital network
connection capable of transmitting data at a rate of 1.544 mbps.
T1 lines are typically leased from local telephone companies
and interLATA carriers by organizations (such as large businesses
and government agencies and colleges) that have heavy external
network traffic. A T1 line is about 24 times "wider"
than a 56/64 kbps, and it is the fastest speed line commonly used
to connect local area networks to the Internet.
T3 line A highspeed
digital network connection capable of transmitting data at a rate
of 44.746 million bits per second (mbps). T3 lines are about 29
times larger than T1 lines, and they can transmit fullmotion,
realtime video and very large databases over a busy network.
The major national interexchange carriers (AT&T, MCI, Sprint)
use T3 lines in their network backbones, but at present there
are very few T3 lines of any length in South Carolina.
TCP Transmission Control Protocol.
The transport layer for the TCP/IP protocol suite on which the
Internet is based. TCP is a connection-oriented protocol.
TCP/IP Transmission Control Protocol over Internet
Protocol. A shorthand term for a widely
used set (suite) of communication protocols that performs the
transfer of data between two computers. TCP/IP is the standard
protocol suite used on the Internet.
WAN Wide Area Network.
A network that covers a large geographic area such as a school
district, county, region, or state.
Web developer An individual
or company that designs, develops, and promotes World-Wide Web
sites for businesses and other organizations. Web development
work can be done by an organization's own employees or contracted
to outside Web developers. Many Internet access providers also
provide Web development services.
Web hosting service A
local, state, regional, or national company or non-profit organization
that operates an Internet computer that hosts or publishes World-Wide
Web sites for businesses and other organizations. Most Internet
access providers also provide Web hosting services.
World-Wide Web A type
of on-line public information delivery system that enables individuals
and organizations to publish text, graphical, video, and audio
information-within a single organization or on the Internet.
In just two years the Web has become the overwhelmingly dominant
form of delivering information and services through the Internet.