Chapter 14: Network Components

Question 1

Analog vs digital signals

Answer 1

analog signals represent data as continuously changing wave values; digital signals encode data in discrete voltage values

Question 2

Reliability of analog vs digital signals

Answer 2

digital signals more reliable than analog signals over a long distance and provides a clear-cut and efficient signaling method because the voltage is either on (1) or not on (0), compared to interpreting the waves of an analog signal

Question 3

Synchronous communications

Answer 3

require a timing component but ensure reliability and higher speeds

Question 4

Asynchronous communications

Answer 4

require no timing component and are simpler to implement

Question 5

baseband technology

Answer 5

uses the entire communication channel for its transmission

Question 6

broadband technology

Answer 6

divides the communication channel into individual and independent subchannels so different types of data can be transmitted simultaneously

Question 7

Coaxial cable

Answer 7

copper core surrounded by a shielding layer and grounding wire, which make it resistant to electromagnetic interference (EMI), provides higher bandwidth, and supports use of longer cable lengths

Question 8

EMI

Answer 8

electromagnetic interference

Question 9

Twisted-pair cable

Answer 9

twisting of the wires, types of insulation used, quality of conductive material, and the shielding of the wire determine the rate at which data can be transmitted

Question 10

Fiber-optic cabling

Answer 10

carries data as light waves, is expensive, can transmit data at high speeds, is difficult to tap into, and is resistant to EMI and RFI; ideal for security protection

Question 11

Fiber-optic cabling uses glasses and so …

Answer 11

has higher transmission speeds which allow signals to travel over longer distances

Question 12

depending on the materials used, network cables may be susceptible to ….

Answer 12

noise, attenuation, and crosstalk

Question 13

line noise

Answer 13

random fluctuations in electrical-magnetic impulses carried along a physical medium

Question 14

attenuation

Answer 14

the loss of signal strength as it travels

Question 15

crosstalk

Answer 15

phenomenon which occurs when electrical signals of one wire spill over to the signals of another wire

Question 16

bandwidth

Answer 16

the amount of information that can be transmitted over a link within a second

Question 17

data throughput

Answer 17

actual amount of data can actually be carried over a real link

Question 18

repeater

Answer 18

provides the simplest type of connectivity because it only repeats electrical signals between cable segments, which enables it to extend a network

Question 19

bridge

Answer 19

LAN device used to connect LAN segments (or VLAN segments) and extends the range of a LAN

Question 20

transparent bridge

Answer 20

starts to learn about the network’s environment as soon as it is powered on and continues to learn as the network changes by examining frames and making entries in its forwarding tables

Question 21

STP

Answer 21

Spanning Tree Protocol

Question 22

Spanning Tree Protocol

Answer 22

ensure forwarded frames do not circle networks forever, provides redundant paths in case a bridge goes down, assigns unique identifiers to each bridge, assigns priority values to these bridges, and calculates path costs

Question 23

SPB

Answer 23

Shortest Path Bridging

Question 24

Shortest Path Bridging protocol

Answer 24

defined in IEEE 802.1aq; more efficient and scalable than STP; used in newer bridges

Question 25

Switches

Answer 25

multiport bridges which typically have additional management features

Question 26

Routers are in layer ....

Answer 26

Layer 3 or network layer

Question 27

Routers are

Answer 27

devices used to connect similar or different networks

Question 28

Routers link ...

Answer 28

two or more network segments, where each segment functions as independent networks

Question 29

router works at the ... layer, works with ... addresses, has more network knowledge than X, Y, Z

Answer 29

network layer, works with IP addresses, and has more network knowledge than bridges, switches, or repeaters

Question 30

gateway

Answer 30

general term for software running on a device which connects two different environments and often acts as a translator for them or restricts their interactions

Question 31

PBX

Answer 31

Private Branch Exchange

Question 32

Private Branch Exchange

Answer 32

private telephone switch located on an organization's property and performs some of the same switching tasks which take place at the telephone company's central office

Question 33

Proxy server

Answer 33

intermediary between the clients which want access to certain services and the servers which provide those services

Question 34

NAC

Answer 34

network access control

Question 35

Network Access Control

Answer 35

any set of policies and controls which restrict access to their networks

Question 36

endpoint

Answer 36

any computing device which communicates through a network and whose principal function is not to mediate communications for other devices on the network

Question 37

CDN

Answer 37

content distribution network

Question 38

content distribution network

Answer 38

consists of multiple servers distributed across a large region, each of which provides content optimized for users closest to it

Question 39

Regular, high-volume traffic, error checking, high-speed, complex and costly implementation

Answer 39

synchronous signaling

Question 40

data transfers happen at lower volumes at unpredictable intervals

Answer 40

asynchronous communications

Question 41

Cheaper than fiber and allows high bandwidths but resistant to electromagnetic interference (EMI)

Answer 41

coaxial cable

Question 42

cable tray with large number of cables running in parallel and close proximity

Answer 42

crosstalk! electrical signals spill over to the signals of another wire in close proximity unless shielded cables are used

Question 43

loss of signal strength as it travels

Answer 43

attenuation; regardless of which type of cabling used, it is inevitable given a long enough distance which is why repeaters were invented

Question 44

bandwidth vs throughput

Answer 44

amount of data that can theoretically be transmitted over a link within a second vs actual amount of data carried over a real link

Question 45

Layer 3 protocols

Answer 45

OSPF (Open Shortest Path First), BGP (Border Gateway Protocol), IS-IS (Intermediate System-to-Intermediate System)

Question 46

IEEE 802.1X protocol specifically addresses issues in .....

Answer 46

network access control; allows devices to connect in a very limited manner (only to the network authenticator) until the device and/or user can be authenticated

Question 47

Multiprotocol Label Switching system

Answer 47

MPLS functionality is built into networking devices to help them move packets between endpoints more efficiently

Question 48

CDN advantages

Answer 48

reduced latency, tailored content to users around the world, DDoS protection bc of the very distributed nature