Digital Communications

Front 1

is a communications system designed to transmit and receive digital information between computers.

Back 1

local-area network (LAN)

Front 2

are the hardware connected to the network, such as personal or microcomputers, printers, large capacity hard drives, and so on

Back 2

Nodes

Front 3

are the communications media, such as twisted-pair wire, coaxial, or fiber-optic cables that connect the nodes

Back 3

Links

Front 4

Advantage twisted-pair cable is?

Back 4

easy to install and costs little on a per-foot basis

Front 5

Twisted pair's disadvantages includes

Back 5

limitations in capacity and speed. It is also susceptible to electrical interference unless its shielded

Front 6

You can use either baseband or broadband transmission methods with

Back 6

Coaxial Cable

Front 7

Coxial Cable examples:

Back 7

RG-11, RG-58, RG-59, RG-62

Front 8

Baseband coaxial systems advantages:

Back 8

inexpensive, easy to install, and have low maintenance.
allow very high data transmission rates.

Front 9

Baseband coaxial systems disadvantages:

Back 9

are limited to transmitting digital signals only

Front 10

broadband coaxial systems advantages:

Back 10

support data, voice, and video signals that may be transmitted simultaneously

Front 11

broadband coaxial systems disadvantages:

Back 11

broadband systems are their higher installation costs and complex maintenance

Front 12

Fiber-Optic Cable advantages:

Back 12

best choice if a secure network is needed.
transmissions are immune to interference caused by electrical or electronic devices.
lasts longer than other types of cable and can carry many more channels.

Front 13

Fiber-Optic Cable disadvantages:

Back 13

high price, poor connectivity, and low flexibility

Front 14

attach personal computers to the LAN, you must connect with a?

Back 14

network interface card (NIC)

Front 15

Is a combination of hardware and software that is used to manage the shared resources of the network

Back 15

server

Front 16

is able to control network traffic as well as the sharing of other resources, such as application programs, disk space, data files, and printers.

Back 16

network server

Front 17

performs the processing of the network control software and the central processing and storage point of the application software and data files of the network

Back 17

file server

Front 18

provide some level of uniformity among computer manufacturers and network vendors

Back 18

OPEN SYSTEM INTERCONNECTION (OSI) REFERENCE MODEL

Front 19

is concerned with the transmission of the unstructured raw bit stream over a physical medium

Back 19

Physical Layer

Front 20

provides error-free transmission of information over the physical medium

Back 20

data-link layer

Front 21

defines the software protocols necessary to exchange data on the network

Back 21

transport level

Front 22

decides which physical pathway the data should take based on network conditions, priorities of service, and other factors

Back 22

network layer

Front 23

makes sure data units are delivered error-free, in sequence, without losses or duplications

Back 23

transport layer

Front 24

allows users on different machines to establish sessions between one another

Back 24

session layer

Front 25

formats data to be presented to the application layer. It can be viewed as the translator for the network

Back 25

presentation layer

Front 26

serves as the window for the application process to access the OSI environment

Back 26

application layer

Front 27

The greatest advantage of your using layer architecture in a network is

Back 27

hardware independence

Front 28

is like a data highway. That is, all components or nodes are connected to the same cable, and the far ends of this cable never meet

Back 28

linear bus topology

Front 29

allow individual nodes to be out of service or to be moved to new locations without disrupting service to the remaining nodes

Back 29

linear bus topology

Front 30

disadvantage of linear bus topology is that

Back 30

must be a minimum distance between workstations to avoid signal interference. Nodes must compete with each other for the use of the bus.
No easy way for the network administrator to run diagnostics on the entire network.
Bus network can be easily compromised by an unauthorized network user.

Front 31

each component is connected directly to the central computer or network server

Back 31

star network

Front 32

star network advantages:

Back 32

New workstations can be easily added to the network without interrupting other nodes.
selected nodes a higher priority status than others.

Front 33

star network disadvantages:

Back 33

reliance on the central computer for performing almost all the functions of the network.

Front 34

connects workstations to a central point called a hub. This hub can support several workstations or hubs which, in turn, can support other workstations

Back 34

DISTRIBUTED STAR

Front 35

DISTRIBUTED STAR advantage:

Back 35

can use inexpensive hubs with long runs of shared cable between hubs, similar to the bus topology

Front 36

This topology allows a node to send a message to another node on the ring. However, the message must be transmitted through each node until it reaches its destination

Back 36

RING NETWORK

Front 37

major disadvantages of ring topologies is

Back 37

the extreme difficultly of adding new workstations while the network is in operation.

Front 38

CSMA

Back 38

Carrier Sense Multiple Access

Front 39

CSMA/CD

Back 39

Carrier Sense Multiple Access with Collision Detection

Front 40

half-duplex protocol that transmits strings of characters at lower speeds over dial-up circuits. The information movement is in one direction at a time, with each data transfer being answered by an acknowledgement

Back 40

Bisync

Front 41

control procedure that sends multiple blocks of data and returns a single acknowledgement for many blocks, thereby increasing the amount of time spent transmitting data

Back 41

SDLC

Front 42

IEEE 802.3

Back 42

Carrier sense multiple access/collision detection (CSMA/CD)

Front 43

IEEE 802.4

Back 43

Token Bus

Front 44

IEEE 802.5

Back 44

Token ring

Front 45

star topology with a CSMA/CD protocol. Its throughput speed is 1Mb per second over twisted-pair cable

Back 45

STARLAN

Front 46

distributed star topology that uses a token passing protocol and either twisted-pair or coaxial cabling. Its throughput speed is 2.5Mb per second

Back 46

ARCnet

Front 47

uses a star ring topology, and is defined by the IEEE 802.5 specification. It has a throughput speed of 4 Mbits per second and 16 Mbit per second.

Back 47

IBM Token Ring Network

Front 48

Optimizing access to services by users.
Maintaining status information of many of the processes.
Error reporting.
Service initialization and service termination of workstations.

Back 48

Control Kernel

Front 49

The most important job of a network operating system (NOS) is to

Back 49

provide file service for the attached computers