[ Pobierz całość w formacie PDF ]
Education—with over seven hours of content to help you design,
build, and maintain networks.
You also have unique options available for including networking
studies as part of your curriculum to expand student opportuni-
ties and help support your campus needs for qualified support
staff. For more information, visit http://www.cisco.com/edu
on the World Wide Web and check out the Cisco Networking
Academies program.
Glossary
ATM
Ethernet
Asynchronous Transfer Mode. Under ATM, multiple
A popular LAN technology that uses CSMA/CD (collision
traffic types (such as voice, video, or data) are
detection) to move packets between workstations
conveyed in fixed-length cells (rather than the random-
and runs over a variety of cable types at 10 Mbps.
Fast Ethernet
length “packets” moved by technologies such as
Ethernet and FDDI). This feature enables very high
Uses the same transmission method as 10-Mbps
speeds, making ATM popular for demanding network
Ethernet (collision detection) but operates at 100 Mbps—
backbones. With networking equipment that has
10 times faster. Fast Ethernet provides a smooth upgrade
recently become available, ATM will also support WAN
path for increasing performance in congested Ethernet
transmissions. This feature makes ATM valuable for
networks, because it can use the same cabling
(if Category 5 cabling is used), applications, and net-
large, dispersed organizations.
Backbone
work management tools. Variations include 100BaseFX,
The part of a network that acts as the primary path for
100BaseT4, and 100BaseTX.
FDDI
traffic moving between, rather than within, networks.
Bandwidth
A Fiber Distributed Data Interface. A LAN technology
The “data-carrying” capacity of a network connection,
based on a 100-Mbps token-passing network running
used as an indication of speed. For example, an Ether-
over fiber-optic cable. Usually reserved for network
net link is capable of moving 10 million bits of data per
backbones in larger organizations.
Frame Relay
second. A Fast Ethernet link can move 100 million bits
of data per second—10 times more bandwidth.
A wide-area network service that provides switched
Bridge
(“on-and-off”) connections between distant locations.
FTP
A device that passes packets between multiple network
segments using the same communications media. If
File Transfer Protocol. A part of the chief Internet
a packet is destined for a user within the sender’s own
protocol “stack” or group (TCP/IP) used for transferring
network segment, the bridge keeps the packet local. If
files from Internet servers to your computer.
HTML
the packet is bound for another segment, the bridge
passes the packet onto the network backbone.
HyperText Markup Language. Document-formatting
Client
language used for preparing documents to be viewed
A networked PC or terminal that shares “services” with
by a tool such as a World Wide Web browser.
HTTP
other PCs. These services are stored on or administered
by a server.
HyperText Transmission Protocol. Protocol that governs
Collision Domain
transmission of formatted documents over the Internet.
In Ethernet, the result of two nodes transmitting simul-
taneously. The frames from each device impact and
are damaged when they meet on the physical media.
30
Hub
Remote Access Server
A device that interconnects clients and servers, repeating
A device that handles multiple incoming calls from
(or amplifying) the signals between them. Hubs act
remote users who need access to central network
as wiring “concentrators” in networks based on star
resources. A remote access server can allow users to
topologies (rather than bus topologies, in which
dial into a network using a single phone number. The
computers are daisy-chained together).
server then finds an open channel and makes a con-
Internet
nection without returning a busy signal.
Router
A massive global network, interconnecting tens of
thousands of computers and networks worldwide,
A device that moves data between different network
it is accessible from any computer with a modem or
segments and can look into a packet header to deter-
router connection and the appropriate software.
mine the best path for the packet to travel. Routers
ISDN
can connect network segments that use different
Integrated Services Digital Network. Communication
protocols. They also allow all users in a network to
protocol offered by telephone companies that permits
share a single connection to the Internet or a WAN.
Server
high-speed connections between computers and
networks in dispersed locations.
A computer or even a software program that provides
LAN
clients with services—such as file storage (file server),
programs (application server), printer sharing (print
Local-area network. Typically, a network or group
server), fax (fax server) or modem sharing (modem
of network segments confined to one building or a
campus. Compare to WAN.
server). Also see “client.”
Modem
Switch
A device that enables a computer to connect to
A device that improves network performance by
other computers and networks using ordinary phone
segmenting the network and reducing competition for
lines. Modems “modulate” the computer’s digital sig-
bandwidth. When a switch port receives data packets,
[ Pobierz całość w formacie PDF ]