Here's a bit of advice... forget the thousands of acronyms,
terms and standards this industry has spawned, and concentrate instead on the theory of
how networks work. If you get in a pinch with jargon, the following glossary should help
get you by.
A-C | D-F | G-I | J-L | M-O | P-R | S-U | V-Z
10BASE-T: The IEEE 802.3i standard specification for
10 Megabits per second (Mbps) Ethernet transmission over Unshielded Twisted Pair (UTP)
wiring, using a star configuration with a hub at the center.
100BASE-T: The IEEE 802.3u standard Ethernet
specification for 100Mbps (Fast Ethernet) transmission using UTP cable.
Adapter: The device that connects a
piece of equipment to the network and controls the electrical protocol for communication
with that network; also called network interface card, or NIC.
Adaptive Technology: An Intel technology
(supported in adapters and switches) that automatically and dynamically customizes product
performance to match network operating conditions, thus helping to optimize network
ATM (Asynchronous Transfer Mode): A
high-speed networking technology that transfers packets of data to transmit various kinds
of information (voice, video, data).
Backbone: The part of the network that
carries the heaviest traffic; it connects LANs, either within a building or across a city
Bandwidth: The maximum amount of data
that a network cable can carry, measured in bits per second (bps).
Baseband: A network transmission
technique that uses voltage to represent data; similar to turning a light switch on and
Bridge: A device that connects two
networks at the OSI Data Link layer and passes data between them; equivalent to a two-port
Broadband: A network transmission
technique that uses radio frequencies on a cable; a broadband cable is typically shared
with other networks or services, such as TV or teleconferencing.
Browser: Client software used to search
information posted on the Web; Netscape* and Microsoft Internet Explorer* are the most
Bus topology: The physical layout of a
network in which all systems connect to a main cable; also known as linear bus.
Client: In a client/server network, a
node (or user workstation) on the network that uses resources provided by a server.
Coaxial cable: A network cable with good
noise immunity; also known as coax or thicknet.
Collision Domain: The maximum length of
the wiring media that allows collision detection. For example, the collision domain in
Fast Ethernet using 100BASE-TX is 205 meters.
CSMA/CD: The acronym for Carrier Sense
Multiple Access with Collision Detection; a LAN transmission technique implemented in
Layer 2 of the OSI model and employed by 10Mbps Ethernet and Fast Ethernet.
Dumb terminal: A monitor and keyboard
that displays information only (as opposed to the processing capability of a PC); usually
connected to a mainframe.
Fast Ethernet: The high-bandwidth
networking technology based on the 802.3 Ethernet standard (100BASE-T); supports 100Mbps
performance, a tenfold increase over original 10Mbps Ethernet (10BASE-T).
FDDI: The acronym for Fiber Distributed
Data Interface; a standard for fiber optic cable.
Fiber optic: A cable that uses light to
communicate; the fastest and most noise-resistant cable available for network wiring, but
also the most expensive.
Frame relay: A high-speed, low-latency
packet switching technology, based on a switched virtual network topology, used for WANs;
popular for LAN-to-LAN connections.
Full-duplex: Allows a packet to be
transmitted and received at the same time.
Gateway: A network station used to
interconnect two or more dissimilar networks or devices; may perform protocol conversion.
Gigabit Ethernet: A developing
technology for 1 gigabit per second (1Gbps) Ethernet; equivalent to 1000Mbps and 10 times
faster than Fast Ethernet.
Half-duplex: Allows packets to be either
transmitted or received, but not both at the same time.
Home page: The main page of a Web site
and the first screen that a visitor sees displayed when connecting to that site; usually
has links to other pages, both within that site and to other sites.
HTML: HyperText Markup Language, the
authoring language of the Internet; used to create Web pages.
Hyperlinks: Embedded "hot
spots" in Web pages that allow users to jump from one document to another related
document, regardless of where it "lives" on the Internet.
Hub: The central wiring concentrator in
a star-configured network; useful for centralized management, the ability to isolate nodes
from disruption and extending the distance of LAN coverage.
IEEE: The Institute of Electrical and
Electronics Engineers, a body that defines standards and specifications.
IP: Internet Protocol, the part of
TCP/IP that governs packet forwarding.
IPX: Internet Packet Exchange, a NetWare
protocol that provides connectionless communications between devices on a network.
ISDN: Integrated Services Digital
Network, a telecommunications standard for sending digitized voice, video and data signals
over the existing public switched telephone network.
ISO: International Standards
Organization, a body that promotes computer standards and developed the OSI's model for
Local: Typically refers to devices
attached to the user's workstation, as opposed to remote devices that are accessed through
Local Area Network (LAN): Workstations
and computers that are tied together in a specific work area in the same general location.
MAC: Media Access Control, the IEEE
specification for the lower sublayer of the OSI Data Link layer; CSMA/CD and Token Ring
are types of MACs.
MAC address: Unique address assigned to
each active infrastructure end station (including adapters, LAN on motherboard, switch
ports and router ports).
MDI (Medium Dependent Interface): The
predefined physical layer interface for 10Mbps Ethernet.
MIB (Management Information Base): A
database of objects that stores information used by SNMP-enabled management devices.
MII (Medium Independent Interface): The
predefined physical layer interface for 100BASE-T.
Network Operating System (NOS): Software
that manages the resources of a network; typically provides file sharing, e-mail, print
services, security measures, etc.
NIC: A Network Interface Card; see
Node: Each of the individual computers
or other devices on the network.
OSI: Open System Interconnection, a LAN
communication model developed by ISO.
Packet: A chunk of data bits and
associated information, including source address and destination address, formatted for
transmitting from one node to another.
Packet analyzer: A network diagnostic
tool that hooks into a LAN and analyzes its traffic; capable of capturing a packet,
examining it and breaking it down into its component parts of destination, origin,
protocol, data, etc.
Print server: An application-specific
computer that manages printers and requests for print services; allows multiple users to
share a network printer.
Print spooler: A software application,
typically installed on a LAN server, that manages multiple print requests.
Protocol: Any defined set of procedures,
conventions or methods that, when adhered to, allow two devices to interoperate; used to
implement LAN services.
Remote execution: The ability to run
programs on remote systems; exporting time-consuming processes to other systems frees up
the local workstation.
Repeater: A device that regenerates and
amplifies signals to create long-distance networks.
Ring topology: A network cabling
configuration in which each system is connected in a series, forming a closed loop.
Router: A device that connects two
networks at the Network layer (Layer 3) of the OSI model; operates like a bridge but also
can choose routes through a network.
RMON: An SNMP standard for managing
network devices; lets network engineers with properly configured SNMP management consoles
view packet information on a port-by-port basis.
Server: A network node that provides
services to client PCs, for example, file access, print spooling or remote execution.
SNMP (Simple Network Management Protocol):
A de facto standard for managing network devices, including adapters, switches, routers,
servers and workstations; garners information from various agents.
Star topology: A network cabling
configuration that uses a central connection point (called a hub), through which all
communication must pass.
Store-and-forward: A switching
technique, used by bridges and switches, in which complete packets of information are
stored in internal buffers before they are sent to another port.
STP: Shielded Twisted Pair; a
thin-diameter network wire, wrapped with a metal sheath for extra protection against
Switching: The process by which packets
are received, stored and transmitted to the appropriate destination port.
TCP/IP: Transmission Control
Protocol/Internet Protocol; a network protocol that breaks messages into manageable chunks
and verifies that they arrive at the correct destination node.
Thick Ethernet: The original Ethernet
cable specification, requiring an AUI connector; noise-resistant, but expensive and
difficult to install.
Thinnet: (Thin Ethernet) A CSMA/CD
network based on thin coaxial cable (also called thin Ethernet) that requires a BNC
connector; based on the 10BASE-2 IEEE standard.
Token passing: A network transmission
method that requires a node to have control of a "token" before it can send
messages; typically fairer than CSMA/CD on busy networks, but more complicated to
Token Ring: IBM's implementation of
token passing, governed by the IEEE 802.5 standard; second most popular network topology
Twisted pair: A popular and low-cost LAN
cabling method, also commonly used for telephone wiring; uses two wires twisted together
to minimize electrical interference (see STP and UTP).
URL: Uniform Resource Locator, the
standard way to write the address of a specific site or piece of information on the Web;
for example, http://www.pcxcomputers.com/.
UTP: Unshielded Twisted Pair; a
thin-diameter network wire that is very popular in network cabling installations.
Virtual terminal: A terminal emulation
program that makes a workstation appear to be a dumb terminal connected to some remote
system, such as a mainframe.
VLANs: Virtual LANs; a switching
technology that enables logical segmentation of switched networks, independent of physical
grouping or collision domains.
Wide Area Network (WAN): A
geographically dispersed network that connects two or more LANs; typically involves
dedicated high-speed phone lines or satellites.
Workgroup (also called segment): A
grouping of workstations, server(s) and any network devices dedicated to similar
functions, using similar applications and/or sharing common resources, and serving as a
subnetwork entity; members may have a common geography or function, e.g., engineering,
marketing, manufacturing and administration.
Workstation: For the purposes of this
guide, a personal computer in a network; also called a client.
X.25: A WAN standard for protocols and
message formats; used to access public packet-switching networks.