Chapter 3 Review Question Solutions
\n1. TRUE or FALSE? The ARPANet, the precursor to today\u2019s Internet, was funded
\nprimarily by the U.S. Department of Defense.
\nTRUE
\n2. TRUE or FALSE? Because the ARPANet utilized ordinary phone lines to connect
\ncomputers over large distances, it was slow compared to existing technologies of the
\ntime.
\nFALSE
\n3. TRUE or FALSE? In a centralized computer network, the failure of a single machine or
\nconnection can isolate large portions of the network.
\nTRUE
\n4. TRUE or FALSE? A router is a special-purpose computer on the Internet that receives
\nmessage packets, access routing information, and passes the packets on towards their
\ndestination.
\nTRUE
\n5. TRUE or FALSE? When a message is broken into packets as transmitted over the
\nInternet, it is guaranteed that all packets will take the same route from source to
\ndestination.
\nFALSE
\n6. TRUE or FALSE? 147.134.2.84 is an example of an IP address.
\nTRUE
\n7. The Internet Society, an international non-profit organization, maintains and enforces
\nstandards for the hardware and software of the Internet.
\nTRUE
\n3.2
\n8. TRUE or FALSE? The World Wide Web was developed in the early 1970s, shortly after
\nthe development of the Internet.
\nFALSE
\n9. TRUE or FALSE? Microsoft marketed the first commercial Web browser.
\nFALSE
\n10. TRUE or FALSE? In the URL http:\/\/balance3e.com\/index.html, the part
\nbalance3e.com identifies the Web server where the page is stored.
\nTRUE
\n11. The Internet of today evolved from the ARPANet of the 1960s and 70s. In what ways is
\nthe Internet similar to the old ARPANet? In what ways is it different?
\nFollowing the initial design of the ARPANet, the Internet is a distributed network that
\nutilizes packet-switching. However, the number of users and variety of uses for the
\nInternet has far exceeded any expectations of the ARPANet, which was designed for use
\nby a small number of military researchers. To accommodate the large number of
\ncomputers on the Internet, it has evolved into a hierarchical network, with high-speed
\nbackbones for transmission between central locations and slower communication lines for
\nlocal connections.
\n12. The Internet is often described as the “Information Superhighway.” Describe how the
\nanalogy of a highway system fits the structure of the Internet.
\nThe backbone connections are analogous to interstate highways, providing fast
\ncommunications between principal destinations. Connected to the backbone are
\ntransmission lines, which provided slower, more limited capabilities and linked
\nsecondary destinations; these transmission lines could be compared to state highways.
\nAdditional connections are required to reach individual computers, in the same way that
\ncity and neighborhood roads are used to link individual houses.
\n13. Paul Baran proposed two groundbreaking design ideas for the structure and behavior of
\nthe ARPANet. Describe these design ideas and the benefits they provide.
\nThe first of Baran\u2019s ideas adopted for the ARPANet was that of a distributed network,
\nwhere control is distributed across a large number of machines. This allows for
\nmessages to be rerouted along alternate connections when a particular computer or
\nconnection fails. Baran\u2019s other idea central to the ARPANet architecture was that of
\npacket-switching, where messages to be sent over the network are first broken into small
\npieces and then sent independently to their final destination. Advantages of this approach
\n3.3
\ninclude a more efficient use of the connections, the ability to react to failures and
\ncongestion, and improved reliability.
\n14. Describe how packet-switching can increase the reliability of a network.
\nIn a packet-switching network, messages to be sent over the network are first broken into
\nsmall pieces known as packets, and these packets are sent independently to their final
\ndestination. If a message is broken into packets and the packets are transmitted
\nindependently, it is probable that at least part of the message will arrive at its destination,
\neven if some failures occur within the network. If the recipient receives only part of the
\nmessage, TCP software on his or her computer can acknowledge the partial message\u2019s
\nreceipt and request retransmission from the sender.
\n15. Internet communications are defined by a set of protocols called TCP\/IP. What do TCP
\nand IP stand for, and what is the role of each protocol in transmitting and receiving
\ninformation?
\nTransmission Control Protocol (TCP) controls the method by which messages are broken
\ndown into packets and then reassembled when they reach their final destination. Internet
\nProtocol (IP), on the other hand, is concerned with labeling the packets for delivery and
\ncontrolling the packets\u2019 paths from sender to recipient.
\n16. What is an IP address? What steps are involved in mapping a computer’s domain name
\n(e.g., www.creighton.edu) to its IP address?
\nAn IP address is a number, usually written as a dotted sequence such as 147.134.2.84.
\nSpecial-purpose computers called domain name servers are used to store mappings
\nbetween domain names and their corresponding IP addresses. When a computer sends a
\nmessage to a destination such as www.creighton.edu, the sending computer first
\ntransmits a request to a domain name server, which matches the recipient\u2019s domain name
\nto an IP address and returns that address.
\n17. Which has grown at a faster rate, the Internet or the Web? Justify your answer.
\nThe data in Figure 3.15 gives somewhat mixed results. If you look at the period from
\n2006 to 2010, the Web has grown at a faster rate, with the number of Web servers
\nincreasing by 133% compared with a 72% increase in Internet-connected computers.
\nMost recently, from 2008 to 2010, the number of Web servers has increased at a smaller
\nrate: 17% versus 33%. If you judge Web size by the number of pages, then the Web is
\ngrowing much faster (from 8 billion pages in 2005 to 40 billion pages in 2009).
\n18. What is hypertext? How are the key ideas of hypertext incorporated into the Web?
\n3.4
\nThe term hypertext refers to documents that interlink text and media, such as images,
\nsounds, and alternate story lines. The Web utilizes hypertext in that Web pages can
\ncontain other media and links to other pages as well.
\n19. What specific features did the Mosaic browser include that were not available in earlier
\nbrowsers? How did these features help make the Web accessible to a larger audience?
\nMosaic employed buttons and clickable links as navigational aids, making the Web easier
\nto traverse. The browser also supported the integration of images and media within pages,
\nwhich enabled developers to create more visually appealing Web documents.
\n20. Describe two factors that contributed to Microsoft\u2019s dominance of the browser market.
\nMicrosoft\u2019s financial position was much stronger than Netscape\u2019s \u2014 due to its success
\nwith other software products, Microsoft possessed vast resources with which to develop
\nand market its browsers. Also, Microsoft was able to leverage its dominance in operating
\nsystems by packaging Internet Explorer as part of Windows.
\n21. What does HTTP stand for, and what is its role in facilitating Web communications?
\nHyperText Transfer Protocol (HTTP) is the protocol that determines how messages
\nexchanged between browsers and servers are formatted.
\n22. The World Wide Web Consortium maintains and regulates Web-related standards and
\noversees the design of Web-based technologies. Visit their Web site (www.w3.org) to
\nreview the organization\u2019s goals and list of technologies under active development.
\nDescribe three technologies (other than HTML, HTTP, and XML) whose development is
\nmanaged by the World Wide Web Consortium.
\nStudent answers will vary.
\n23. How does caching improve the performance of a Web browser? Does caching reduce the
\nnumber of interactions that take place between the browser and the Web server?
\nWhen a page or image is first downloaded, it is stored in a temporary directory on the
\nuser’s computer. The next time that page or image is requested, the browser first checks
\nto see if it has a copy stored locally in the cache, and, if so, whether the copy is up-to-date
\n(this is accomplished by contacting the server and asking how recently the page was
\nchanged). If an up-to-date copy is stored locally, then the browser can display this copy,
\ninstead of downloading the original. Caching can make downloading a new copy
\nunnecessary, but it still requires a check to see if the cached page is up-to-date.<\/p>\n","protected":false},"excerpt":{"rendered":"
Chapter 3 Review Question Solutions 1. TRUE or FALSE? The ARPANet, the precursor to today\u2019s Internet, was funded primarily by the U.S. Department of Defense. TRUE 2. TRUE or FALSE? Because the ARPANet utilized ordinary phone lines to connect computers over large distances, it was slow compared to existing technologies of the time. FALSE 3. […]<\/p>\n","protected":false},"author":274,"featured_media":0,"parent":558,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_mi_skip_tracking":false},"_links":{"self":[{"href":"https:\/\/sites.evergreen.edu\/compcog15\/wp-json\/wp\/v2\/pages\/826"}],"collection":[{"href":"https:\/\/sites.evergreen.edu\/compcog15\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.evergreen.edu\/compcog15\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.evergreen.edu\/compcog15\/wp-json\/wp\/v2\/users\/274"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.evergreen.edu\/compcog15\/wp-json\/wp\/v2\/comments?post=826"}],"version-history":[{"count":0,"href":"https:\/\/sites.evergreen.edu\/compcog15\/wp-json\/wp\/v2\/pages\/826\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/sites.evergreen.edu\/compcog15\/wp-json\/wp\/v2\/pages\/558"}],"wp:attachment":[{"href":"https:\/\/sites.evergreen.edu\/compcog15\/wp-json\/wp\/v2\/media?parent=826"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}