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Chapter 1 Computer Networks and the Internet networks use VC. numbers to forward packets toward their1．The ( ) is a worldwide computer network, that is, a network that destination.interconnects millions of computing devices throughout the world. D datagram networks use VC. numbers and virtual-circuit networks ppt3 use destination addresses to forward packets toward their destination.A public Internet 9．In the following options, which one is not a guided media? ( )B Intranet A twisted-pair wireC switch net B fiber opticsD television net C coaxial cable2．Which kind of media is not a guided media? ( ) D satelliteA twisted-pair copper wire 10．Processing delay does not include the time to ( ).B a coaxial cable A examine the packet’s headerC fiber optics B wait to transmit the packet onto the linkD digital satellite channel C determine where to direct the packetD check bit-error in the packet3．Which kind of media is a guided media? ( )11．In the following four descriptions, which one is correct? ( )A geostationary satelliteB low-altitude satelliteC fiber opticsD wireless LAN A The traffic intensity must be greater than 1.B The fraction of lost packets increases as the traffic intensity decreases.C If the traffic intensity is close to zero, the average queuing delay 4．The units of data exchanged by a link-layer protocol are called ( ).will be close to zero. A FramesD If the traffic intensity is close to one, the average queuing delay B Segmentswill be close to one. C Datagrams12．The Internet’s network layer is responsible for moving network-layer D bit streamspackets known as ( ) from one host to another. 5．Which of the following option belongs to the circuit-switched networks?A frame ( )B datagram A FDMC segment B TDMD message C VC networks13．The protocols of various layers are called ( ). D both A and BA the protocol stack 6．( )makes sure that neither side of a connection overwhelms the otherB TCP/IPside by sending too many packets too fast.C ISPA Reliable data transferD network protocolB Flow control14．There are two classes of packet-switched networks: ( ) networks andC Congestion controlvirtual-circuit networks.D Handshaking procedureA datagram7．( ) means that the switch must receive the entire packet before it canB circuit-switchedbegin to transmit the first bit of the packet onto the outbound link.C television A Store-and-forward transmissionB FDMD telephoneC End-to-end connection 15．Access networks can be loosely classified into three categories:D TDM residential access, company access and ( ) access.8．Datagram networks and virtual-circuit networks differ in that ( ).A cabledA datagram networks are circuit-switched networks, andB wirelessvirtual-circuit networks are packet-switched networks.B datagram networks are packet-switched networks, andC campusD city areavirtual-circuit networks are circuit-switched networks.Question 16～17 C datagram networks use destination addresses and virtual-circuit1D distributed applicationsSuppose, a is the average rate at which packets arrive at the queue, R is24．The Internet provides two services to its distributed applications: a the transmission rate, and all packets consist of L bits, then the trafficintensity is ( 16 ), and it should no greater than ( 17 ). connectionless unreliable service and () service.A flow control16． A LR／aB connection-oriented reliableB La／RC congestion controlC Ra／LD TCP25．It defines the format and the order of messages exchanged between twoD LR／aor more communicating entities, as well as the actions taken on the 17．A 2B 1 transmission and/or receipt of a message or other event. The sentence describes ( ).C 0A InternetD -1B protocol 18．In the Internet, the equivalent concept to end systems is ( ).C intranet A hostsD network B servers26．In the following options, which does not define in protocol? ( )C clientsA the format of messages exchanged between two or more D routerscommunicating entities 19．In the Internet, end systems are connected together by ( ).B the order of messages exchanged between two or more A copper wirecommunicating entities B coaxial cableC the actions taken on the transmission of a message or other eventC communication linksD the transmission signals are digital signals or analog signals 模拟D fiber optics信号20．End systems access to the Internet through its ( ).27．In the following options, which is defined in protocol? ( ) A modemsA the actions taken on the transmission and/or receipt of a message orB protocolsother eventC ISPB the objects exchanged between communicating entities D socketsC the content in the exchanged messages21．End systems, packet switches, and other pieces of the Internet, run ( )D the location of the hosts that control the sending and receiving of information within the28．In the following options, which does not belong to the network edge?Internet.( )A programsA end systemsB processesB routersC applicationsC clientsD protocolsD servers22．There are many private networks, such as many corporate and29．In the following options, which belongs to the network core? ( ) government networks, whose hosts cannot exchange messages withA end systemshosts outside of the private network. These private networks are oftenB routersreferred to as ( ).C clientsA internetsD serversB LAN30．In the following options, which is not the bundled with the Internet ’s C intranetsconnection-oriented service? ( ) D WANA reliable data transfer23．The internet allows ( ) running on its end systems to exchange dataB guarantee of the transmission timewith each other.C flow control***A clients applicationsD congestion-controlB server applications31．An application can rely on the connection to deliver all of its data C P2P applicationswithout error and in the proper order. The sentence describes ( ).2***A flow control C data switchingB congestion-control D message switchingC reliable data transfer 40．In ( ) networks, the resources needed along a path to provide forD connection-oriented service communication between the end system are reserved for the duration 持续of the communication session. 32．It makes sure that neither side of a connection overwhelms 淹没压倒the other side by sending too many packets too fast. The sentence A packet-switcheddescribes ( ). B data-switchedA flow control C circuit-switchedB congestion-control D message-switchedC connection-oriented service 41．In ( ) networks, the resources are not reserved; a session’s messagesD reliable data transfer use the resources on demand, and as a consequence, may have to wait 33．It helps prevent the Internet from entering a state of gridlock. When a for access to communication link.packet switch becomes congested, its buffers can overflow and packet A packet-switchedloss can occur. The sentence describes ( ). B data-switchedA flow control C circuit-switchedB congestion-control D message-switchedC connection-oriented service 42．In a circuit-switched network, if each link has n circuits, for each linkD reliable data transfer used by the end-to-end connection, the connection gets ( ) of the 34．The Internet’s connection-oriented service has a name, it is ( ). link ’s bandwidth for the duration of the connection.A TCP A a fraction 1/nB UDP B allC TCP/IP C 1/2D IP D n times35．In the following options, which service does not be provided to an 43．For ( ), the transmission rate of a circuit is equal to the frame rate application by TCP?( ) multiplied by the number of bits in a slot.A reliable transport A CDMAB flow control B packet-switched networkC video conferencing C TDMD congestion control D FDM36．The Internet’s connectionless service is called ( ). 44．( ) means that the switch must receive the entire packet before it canA TCP begin to transmit the first bit of the packet onto the outbound link.B UDP A Queuing delayC TCP/IP B Store-and-forward transmissionD IP C Packet loss37．In the following options, which does not use TCP?( ) D PropagationA SMTP 45．The network that forwards packets according to host destinationB internet telephone addresses is called ( ) network.C FTP A circuit-switchedD HTTP B packet-switched38．In the following options, which does not use UDP?( ) C virtual-circuitA Internet phone D datagramB video conferencing 46．The network that forwards packets according to virtual-circuit numbersC streaming multimedia is called ( ) network.D telnet A circuit-switched39．There are two fundamental approaches to building a network core, ( ) B packet-switchedand packet switching. C virtual-circuitA electrical current switching D datagramB circuit switching3。
Computing Essentials 2008课后练习题答案详解Chapter 1: Information Technology, The Internet, and Y ouCrossword Puzzle Answers: (p22)Across1 、The most essential part of an information system. People信息系统最基本的部分。
人7 、Coordinates computer resources. Operating System协调计算机资源。
操作系统10 、Modifies signals for processing. Modem修改信号以便处理。
调制解调器12 、Data that has been processed by the computer. Information计算机处理过的数据。
信息13 、Unprocessed facts. Data没处理过的事实。
数据14 、Notebook computer that accepts handwritten input.. Tablet PC可以用手写输入的笔记本电脑。
平板电脑DownNum. Clue Answer2 、Uses computers to become more productive. End User使用电脑变得更有效率。
终端用户3 、Rules or guidelines to follow when using software, hardware, and data. Procedures使用软件，硬件和数据时遵循的规则或指引。
指令说明书4 、Created by word processors. Document Files文字处理创建出来的。
文档文件5 、Specialized programs that allow input and output devices to communicate. Device Drivers 允许输入和输出设备通信的专业程序。
Chapter 11.Raw, unprocessed facts, including text, numbers, images, and sounds.a.data2.Perform specific tasks related to managing computer resources。
h。
utilities3.Type of application programs that are more narrowly focused on specificdisciplines and occupations。
f。
specialized4.Also known as servers. b。
midrange computers5.The most widely used handheld computers are smartphones and ___。
d。
PDAs6.Type of memory that is sometimes referred to as temporary storagebecause its contents will typically be lost if the electrical power to the computer is disrupted. e。
RAM7.The most important kinds of secondary media are hard disks，solid—statestorage, and ___。
c。
optical disks8.The type of solid—state drive widely used for transporting data andinformation between computers and a variety of specialty devices。
g. USB9.Type of file created by electronic spreadsheets to analyze things likebudgets and to predict sales。
Homework of Chapter One1. Chapter 1 Multiple ChoiceSelect the best answer for each question below. When you are finished, check your answers by clicking the 'Check Answers' button at the bottom of the page.1. People, procedures, software, hardware, and data are the five parts of a(n)competency systemcomputer systeminformation system✔software system2. Procedures are typically documented in manuals written bycomputer specialists✔end usersMicrosoftservice providers3. Which of the following is an example of connectivity?datahard diskInternet✔power cord4. Windows 7 is an example of a(n)application softwarebrowseroperating system✔shareware5. The most powerful type of computer.mainframe computersmicrocomputersminicomputerssupercomputers✔6. The system component that controls and manipulates data in order to produce information is called thekeyboardmicroprocessor✔monitormouse7. These devices translate data and programs that humans can understand into a form that the computer can process.displayinput✔outputpointer8. A DVD is an example of a(n)hard diskoptical disc✔output devicesolid-state storage device9. This type of file is created by word processors.worksheetdocument✔databasepresentation10. Many experts are predicting that this revolution is expected to dramatically affect the way we communicate and use computer technology.graphicsinputmemorywireless✔2. Chapter 1 MatchingMatch the definitions with the terms in the box to the right by entering the letter for each term next to its correct definition below.1. e Guidelines people follow when using software.2. f Consists of the step-by-step instructions that tell the computer how to do its work.3. i Software that enables the application software to interact with the computer hardware.4. h The most powerful type of computer.5. a The least powerful and most widely used type of computer.6. c Translates the processed information from the computer into a form that humans can understand.7. g Holds data and programs even after electrical power to the system has been turned off.9. d A type of handheld computer.10. j The largest network in the world.3. Chapter 1 Open-Ended Questions⑴. Explain the five parts of an information system. What part do people play in this system?An information system typically consists of: people, procedures, software, hardware, data, and connectivity. Information systems are used by people in order to increase productivity. Procedures are rules or guidelines for people to follow when using software, hardware, and data. Software is a program that contains the step-by-step instructions that tell the computer how to do its work. Hardware consists of the physical equipment that processes the data to create information. Data consists of raw unprocessed facts, including text, numbers, images, and sounds. Almost all of today's computer systems add an additional part to the information system. This part, called connectivity,typically uses the Internet and allows users to greatly expand the capability and usefulness of their information systems.⑵. What is system software? What kinds of programs are included in system software?System software is “background” software that enables the application software to interact with the computer. System software consists of the operating system, utilities, device drivers, and language translators. It works with application software to handle the majority of technical details.⑶. Define and compare basic and specialized application software.- Describe some different types of basic applications.- Describe some types of specialized applications.Basic or general-purpose applications are widely used in a large number of careers. One of these general-purpose applications is a browser to navigate, explore, and find information on the Internet.Other basic a pplications are word processors, spreadsheets, database management systems, and presentation graphics.Specialized applications are programs that are narrowly focused on specific disciplines and occupations. Some of the best known are multimedia, Web authoring, graphics, virtual reality, and artificial intelligence.⑷. Describe the different types of computers.- What is the most common type?- What are the types of microcomputers?There are four types of computers: supercomputers, mainframe computers, midrange and microcomputers.Microcomputers are the least powerful, yet the most widely used type of computer.There are four types of microcomputers: desktop computers, notebooks, tablets, and handheld computers.⑸. What is connectivity? What are wireless devices and the wireless revolution? What is a computer network? What are the Internet and the Web? What is cloud computing?Connectivity is the capability of the microcomputer to use information from the world beyond one’s desk. Data and information can be sent over telephone or cable lines and through the air so that computers can talk to each other and share information.Wireless devices are wireless mouse, wireless network card and wireless modem etc.Wireless revolution is a revolution that is expected to dramatically affect the way we communicate and use computer technology.Computer network is a communication system connecting two or more computers and their peripheral devices to exchange information and share resources.Internet is a huge computer network available to everyone with a microcomputer and a means to connect to it. It is the actual physical network made up of wires, cables, and satellites as opposed to the Web, which is the multimedia interface to resources available on the Internet.Cloud computing is that data are stored at a server on the Internet and available anywhere the Internet can be accessed.4. Chapter 1 True / False Questions1. The parts of an information system are: people, procedures, software, hardware, data, and connectivity.True False2. The purpose of software is to convert data into information.True False3. Software is another name for a program or programs.True False4. To be a competent computer user, you must understand the essentials of information technology (IT).True False5. Application software is "background" software which helps the computer manage its own internal resources.True False6. System software is a collection of programs.True False7. Antivirus software is a Windows utility that is unnecessary as long as you are careful browsing the Internet.True False8. System software might be described as end user software.True False9. A browser is an example of system software.True False10. Another name for a midrange computer is server.True False5. Chapter 1 Fill in the Blank Questions1. Computer _competency_ refers to acquiring computer-related skills.2. In an information system, the rules or guidelines for people to follow are called _procedures_.3. _Hardware_ is the component of the information system that is described as the equipment that processes data to create information.4. The component of the information system that is described as raw, unprocessed facts, including text, numbers, images, and sounds, is called _ data_.5. _ System software_ is a collection of programs that helps the computer manage its own resources and enables application software to interact with computer hardware.6. _Device drivers_ are classified under system software and are specialized programs designed to allow input or output devices to communicate with the rest of the computer system.7. Application software can be categorized as either general-purpose applications, specialized applications or _ mobile_ applications.8. The general-purpose application used to navigate, explore, and find information on the Internet is called a _ browser_.9. _Mainframe_ computers are not nearly as powerful as supercomputers, but are capable of great processing speeds and data storage.10. The four types of microcomputers are: _desktop_ computers, notebooks, tablets, and handheld computers.。
