Business Driven Data Communications (Gendron)

Chapter 1 ICT Introductory Concepts

1.1 Multiple Choice Questions

1) 42.18.248 is an ______address.

A) IP

B) ethernet

C) Either A or B

D) Neither A nor B

Answer: A

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2) When a fluorescent light interferes with UTP transmission, this is ______.

A) terminal crosstalk interference

B) EMI

C) crosstalk interference

D) All of the above

Answer: B

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3) Internet infrastructure standards are created by the ______.

A) Internet Association

B) OSI

C) ISO

D) IETF

Answer: D

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4) In optical fiber, light travels through the ______.

A) cladding

B) core

C) buffer

D) None of the above

Answer: B

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5) The ______protocol provides an encrypted connection to a remote computer that typically allows login and commands to be executed on the remote computer.

A) DNS

B) DHCP

C) SSL

D) SSH

Answer: D

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6) Today, the main benefit of optical fiber compared to UTP is ______.

A) the ability to transmit signals faster

B) lower cost

C) the ability to span greater distances

D) durability

Answer: C

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7) In the UTP wiring used in LANs, how many wire pairs are there in a cord?

A) 1

B) 2

C) 4

D) 8

Answer: C

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8) When one pair in a UTP cord interferes with signals in other pairs, this is ______.

A) EMI

B) crosstalk interference

C) internal noise

D) Both A and B

Answer: D

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9) In an internet, different individual networks are connected by ______.

A) trunk lines

B) carrier switches

C) routers

D) All of the above

Answer: D

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10) Routers make packet forwarding decisions based on a packet's ______.

A) destination IP address

B) source IP address

C) Both A and B

D) Neither A nor B

Answer: A

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11) Which layer in the TCP/IP-OSI hybrid architecture governs end-to-end transmission between two hosts across an internet?

A) The Internet Layer

B) The Transport Layer

C) Both A and B

D) Neither A nor B

Answer: B

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12) ______the physical arrangement of a network's computers, switches, routers, and transmission links.

A) Physical Layer standards are

B) Network architecture is

C) Network layout is

D) Network typology is

Answer: D

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13) Which of the following is reliable?

A) UDP

B) TCP

C) Both A and B

D) Neither A nor B

Answer: B

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14) In LANs, optical fiber is typically used in ______.

A) access lines

B) trunk lines

C) Both A and B

D) None of the above

Answer: B

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15) A noise spike is ______.

A) the maximum noise energy

B) a large brief increase in the noise energy

C) the average noise energy

D) the minimum noise energy

Answer: B

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16) Which of the following is connectionless?

A) TCP

B) IP

C) Both A and B

D) None of the above

Answer: B

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17) Routers are usually connected in a ______typology.

A) point-to-point

B) mesh

C) star

D) ring

Answer: B

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18) ______operates at the Internet Layer.

A) TCP

B) IP

C) Both A and B

D) Neither A nor B

Answer: B

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19) A(n) ______specifies a particular application on a particular host.

A) port number

B) IP address

C) socket

D) None of the above.

Answer: C

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20) T-1 leased lines run at a speed of about ______.

A) 10 kbps

B) 50 kbps

C) 750 kbps

D) 1.5 Mbps

Answer: D

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21) Because of greater distances, WAN transmission speeds are ______LAN transmission speeds.

A) faster than

B) about the same as

C) slower than

D) much faster than

Answer: C

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22) UDP ______.

A) is unreliable

B) performs error checking, but not error correction

C) Both A and B

D) Neither A nor B

Answer: C

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23) A POP is ______.

A) a publicly owned telephone company

B) a sudden electrical noise in a telephone circuit

C) a jump in a hop-by-hop transmission

D) a place where telephone carriers interconnect

Answer: D

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24) A ______connection is a point-to-point typology that allows two hosts or devices to communicate through a circuit that interconnects the devices.

A) modem

B) codec

C) bandpass filter

D) All of the above

Answer: A

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25) The dominant scheme for encoding data by a computer is ______.

A) ISO 8858-1

B) JCT1

C) Unicode

D) None of the above

Answer: C

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26) Analog data include ______.

A) sound

B) temperature

C) time

D) All of the above

Answer: D

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27) Bits are commonly grouped into sets of ______bytes, called ______.

A) 4, quartets

B) 6, sextets

C) 8, octets

D) None of the above

Answer: C

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28) ______is a special case of EMI in which conductors in a cable interfere with each other.

A) Attenuation

B) Noise

C) Crosstalk

D) Signal-to-noise

Answer: C

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29) As signals propagate they become weaker due to which propagation effect?

A) EMI

B) Crosstalk

C) Attenuation

D) Signal-to-noise

Answer: C

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30) A signal transmitted one bit at a time is known as ______communication.

A) serial

B) parallel

C) full-duplex

D) half-duplex

Answer: A

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31) ______allows communication simultaneously between two hosts.

A) Serial

B) Parallel

C) Full-duplex

D) Half-duplex

Answer: C

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32) A(n) ______can be used to synchronize a receiver to an incoming data stream.

A) sync word

B) bit

C) octet

D) None of the above

Answer: A

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33) The process by which digital data are converted to sound is known as ______.

A) multiplexing

B) modulation

C) demodulation

D) Both A and B

Answer: B

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34) A ______is an example of a modulator.

A) modem

B) router

C) switch

D) None of the above

Answer: A

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35) Telecommunications is measured in ______per second and in multiples of ______.

A) Mbps, 1000

B) bits, 1000

C) bits, 1024

D) Mbps, 1024

Answer: B

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36) T-3 carrier circuits offer speeds of about ______.

A) 1544 kbps

B) 10 Mbps

C) 43000 kbps

D) 104 Mbps

Answer: C

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37) T-1, T-3, and DSL are all examples of ______.

A) internet service providers

B) frequency ranges

C) carrier circuits

D) None of the above

Answer: C

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38) By following standards and protocols when manufacturing hardware, vendors ensure ______of their products.

A) interoperability

B) low cost

C) ease of use

D) interconnectedness

Answer: A

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39) The ______portion of the hybrid architecture involves Layers 1 and 2, while the ______portion deals with Layers 3 through 5.

A) TCP/IP, OSI

B) OSI, TCP/IP

C) TCP, IP

D) None of the above

Answer: B

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40) The ______mandate that electronic equipment may not emanate more than a specified level of radio interference.

A) IEEE

B) ISOC

C) ITU-T

D) FCC

Answer: D

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41) ______is the correct order for the geographic scope of computer networks from smallest to largest.

A) WAN, MAN, LAN

B) LAN, MAN, WAN

C) LAN, WAN, MAN

D) MAN, WAN, LAN

Answer: C

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42) The ISO committee that governs information technology that are applied to Layers 1 and 2 of the hybrid TCP/IP-OSI architecture is the ______.

A) ITU-T

B) JCT1

C) ATM

D) IEEE

Answer: B

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43) ______are examples of Layer 5 devices, while ______are examples of Layer 2 devices.

A) Hosts, hubs

B) Hubs, switches

C) Routers, hosts

D) Hosts, switches

Answer: D

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44) A network where all hosts are attached to one common media that allows communication among the hosts is known as a ______typology.

A) point-to-point

B) bus

C) star

D) mesh

Answer: B

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45) A ______network typology is one that uses a series of interconnecting routers that creates multiple pathways between points on a network.

A) star

B) ring

C) mesh

D) point-to-point

Answer: C

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46) The ______network typology is the most common LAN typology in which hosts are interconnected through a series of hubs and switches.

A) bus

B) star

C) point-to-point

D) mesh

Answer: B

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47) The worldwide phone system is based on ______switching, where an electrical circuit is created each time data are sent.

A) packet

B) circuit

C) Both A and B

D) Neither A nor B

Answer: B

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48) In the worldwide phone system, the media between the customer premises and the local switch is called the ______, while a carrier circuit that interconnects switches is called a ______.

A) local loop, trunk line

B) trunk line, local loop

C) trunk, loop line

D) loop line, trunk

Answer: A

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49) A ______is any 5 layer telecommunication device capable of propagating data.

A) router

B) hub

C) host

D) switch

Answer: C

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50) The process of converting human-friendly names into numeric addresses is known as ______.

A) addressing

B) encapsulation

C) decapsulation

D) name resolution

Answer: D

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51) The process of putting a message inside of another message so it can be transmitted is called ______.

A) transport

B) decapsulation

C) TCP

D) None of the above

Answer: D

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52) ______ports are in the range of 49152-65535 and are randomly chosen by a host as source ports.

A) Registered

B) Well-known

C) Ephemeral

D) Transport

Answer: C

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53) IP_ADDRESS:PORT_NUMBER represents a ______.

A) transport port

B) PDU

C) socket

D) None of the above

Answer: C

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54) ______Network Layers are needed to carry a message across the Internet.

A) Within

B) Among

C) Between

D) End-to-End

Answer: C

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55) In order to get a message from a sending host to a receiving host, ______layers of the TCP/IP-OSI architecture are needed.

A) 2

B) 3

C) 4

D) 5

Answer: D

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56) The Data Link Layer is layer number ______.

A) 4

B) 2

C) 3

D) 5

Answer: B

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57) The ______Layer is responsible for signaling.

A) Application

B) Internet

C) Physical

D) Data Link

Answer: C

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58) The ______Layer is responsible for between-network routing.

A) Application

B) Internet

C) Physical

D) Data Link

Answer: B

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59) ______is a WAN technology used to interconnect LANs.

A) Point-to-Point

B) Fiber Distributed Data Interface

C) Frame Relay

D) TCP

Answer: C

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60) The purpose of DHCP is to:

A) provide an encrypted connection to a remote computer.

B) provide secure communications for Internet communication.

C) allow a local client to access e-mail on a remote server.

D) assign an IP address and other identifiers to a host.

Answer: D

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1.2 True/False Questions

1) Hardware network addresses are called MAC addresses.

Answer: TRUE

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2) A protocol detects errors but it does not correct them. It is reliable.

Answer: FALSE

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3) Transmission speed normally is measured in bits per second.

Answer: TRUE

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4) Application Layer standards govern how two applications work with each other, even if they are from different vendors.

Answer: TRUE

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5) For their transmission medium, cable television companies primarily use coaxial cable to the premise.

Answer: TRUE

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6) ICT infrastructure includes components directly accessed by the user and the back office components that provide network services and network connectivity.

Answer: TRUE

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7) Technology infrastructure affects both internal operations and external interactions with suppliers, distributors, and customers.

Answer: TRUE

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8) A LAN is generally used when a business wants to communicate from one building to another when those buildings are separated by a large distance.

Answer: FALSE

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9) Switches are Layer 3 devices that allow communication with a LAN.

Answer: FALSE

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10) The PDU at Layer 4 is known as a TCPSegment or UDP Datagram.

Answer: TRUE

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1.3 Essay Questions

1) Explain the differences between digital and analog data, including why they are important and how they are represented.

Answer: Analog data are also known as "continuous data" and include metrics such as sound, temperature, time, and weight. These data are continuous because all numbers, including fractions, are included. Digital data are a representation of real-world analog data and are needed for a computer to manipulate, store, and transmit that information. In order to convert analog data into digital data, the data is coded as a number of bits. The bits are commonly grouped into sets of 8 bytes, called octets, which are the basis of digital character representation.

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2) Define interoperability and discuss how it is important for vendors and customers.

Answer: The key to making ICT hardware work is interoperability. Interoperability means that vendors must build hardware that seamlessly works together by following guidelines, called standards, which dictate how their hardware must operate. The vendor is responsible for the design and manufacture of its equipment, but in order to be interoperable it must operate the same as any other hardware that follows the same standards. Hardware may have differences, such as the size and shape of their components, or the inclusion of vendor-specific options, but in order to interoperate, they must adhere to a governing set of standards. When ICT is built in accordance with existing standards, competition is affected. Standards create a marketplace for hardware and software because multiple vendors offer solutions that do the same or similar functions. These standards force vendors to compete on price, availability of options, and other features. In this competitive market, vendors have an incentive to innovate their products and compete on price. This competitive marketplace is good for consumers because it can motivate vendors to create innovative products as well as cause more attractive pricing.

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3) Describe half- and full-duplex transmission and how they differ.

Answer: When two telecommunication devices communicate, it is possible to transmit in either full or half duplex. Both half- and full-duplex communications allow for communication in both directions. The difference is whether you can transmit in both directions simultaneously, or if you can only transmit in one direction at a time. In half-duplex communication, only one party can be transmitting at a time, while in full-duplex communication both parties can transmit simultaneously.

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4) Describe addressing and name resolution and why they are important.

Answer: Humans generally cannot remember long strings of numbers while computers operate by manipulating numbers and remember them quite well. In order to make information easily available, human-friendly names are used in place of numeric addresses. These names are called Uniform Resource Locaters (URL), which include names such as or as well as hosts and other names. When these names are used they need to be converted into numeric addresses, called IP addresses. The process of converting human-friendly names into numeric addresses is called name resolution.

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5) Summarize a web page request from a host in the TCP/IP-OSI architecture, describing the major role of each layer and identify the common protocols used.

Answer: At Layer 5 the sending host would prepare the HTTP Request message. The goal would be to get a web site to send back its web page. The protocol would be HTTP, and the application would be a web browser. The sending host would then send the message down to Layer 4.

Layer 4 would then encapsulate the application message received from Layer 5 into a TCP Segment, which is the PDU at Layer 4. This Layer is largely responsible for between-network error control, so the sending host will communicate with the transport layer on the receiving host so it can make sure that the information sent is the same as what is received. Common protocols include TCP, UDP, and ICMP.

Layer 3 is then responsible for end-to-end, between-network routing, so the Layer receives the segment from Layer 4 and encapsulates it into a PDU called a packet. The sending host at the Internet layer will communicate with the Internet layer of the receiving host in order to get the packet from the source to the destination host. Common protocols include IP, IPSEC, and ARP.

Layer 2 handles communication within a single LAN, so the Data Link Layer receives the packet from Layer 3 and encapsulates it into a PDU called a frame. Common protocols include Ethernet, ATM, 802.11.

At this point, we have a frame that needs to be propagated within a network. Layer 1, the Physical Layer, is responsible for this propagation and uses different types of propagation methods to send the request to the receiving host. The receiving host then decapsulates the message in the reverse order and returns the web page to the requesting host computer. Common protocols include data encoding and transmission standards.

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