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Chapter 12: Wide Area Networks Key
1. Industry convention describes a WAN as a network that spans a large geographical distance.
2. The largest example of a WAN is the public Internet, but many other types of WANs exist.
3. Local area networking is sometimes referred to as enterprise networking,
4. IBM’s Systems Network Architecture (SNA) and Digital Equipment Corporation’s DECnet networking
architectures provided a set of protocols and used computers and other networked devices manufactured by a
single vendor in the 1970s.
5. During the 1970s, there was complete interoperability between computing devices made by different
manufacturers.
6. Circuit switching is an important general concept of computer networking and is the sole switching approach
used by the most popular WAN: the Internet.
7. A packet contains the actual information content to be transmitted, such as an electronic mail message, as
well as supplementary overhead information, such as the order of the packet, the sender’s binary address and
the binary address of the packet’s destination.
8. In one type of networking approach, known as connectionless packet switching, a dedicated end-to-end
physical connection is established for the duration of data transmission.
9. One goal of routers is to minimize hops, the number of times a packet traverses various routers as it is
10. The circuit-switching approach establishes a physical, dedicated end-to-end path through the network
between a caller and receiver, and maintains the path for the entirety of the call.
11. The circuit-switching approach uses resources more efficiently than the packet-switching approach because
no single user can exclusively occupy a given path.
12. In the United States, the development of the packet-switching approach was influenced by concerns about
survivable communication networks during the Cold War.
13. Packet switching was independently developed by Paul Baran at RAND Corporation in the United States
and by Donald Davies at the National Physical Laboratory in the United Kingdom.
14. Protocols are the rules that enable information exchange over a network, including how many bits make up
a binary network address, how to place information in standard formats that anyone can read, and rules for
performing error checking over the network.
15. TCP/IP is not an open protocol—i.e. it is controlled by a single vendor, it is not available for any
manufacturer to use, and it does not enable universal access to the Internet.
16. A repeater is an intelligent switching device that determines how to direct (or route) a packet across a
network, based on the packet’s destination address and network conditions.
17. The addresses that routers analyze over the Internet are called IP (Internet Protocol) addresses; routers make
packet forwarding decisions based on these IP addresses.
18. A computing device on a local area network has an IP address that is physically associated with a LAN
adapter, such as an Ethernet card.
19. When an information packet arrives from a network at any given router, the router reads the destination IP
address. The router “looks up” information in a routing table to direct the packet in the most efficient way
toward its destination, either by sending it to another router or by leaving the packet on its current network to
route to its destination.
20. A device called a CSU/DSU (Channel Service Unit/Data Service Unit) is an important network component
between an edge router and a dedicated transmission line.
21. The equipment at a customer location that serves as the demarcation point between a local network and a
service provider’s WAN is often called customer premises equipment (CPE).
22. The primary disadvantage of a private network is security. i.e. a private network is always less secure than a
public network.
23. A VPN is a private network arrangement that runs over a public telecommunications network, usually the
Internet.
24. In frame relay services, a software defined (virtual) path is set between two devices on the network, and the
devices are expected to exchange information.
25. Frame relay service providers guarantee their customers a minimum bandwidth known as the committed
information rate (CIR), along with a certain allotment of ad hoc, higher bandwidth called the extended
information rate (EIR).
26. Historically, frame relay originated as an improvement over an older WAN technology known as Ethernet.
27. WAN service providers also offer Asynchronous Transfer Mode (ATM), a network alternative that formats
information into variable-length packets.
28. ATM cells have a total length of 63 bytes: ten bytes for overhead and 3 bytes reserved for the actual data
being transmitted.
29. MPLS service can handle variable-length packets, in contrast with ATM, which transmits fixed-length
cells.
30. The data rate supported by a T-1 line is 1.544 Mbps.
31. The data rate supported by a T-3 line is 100 Mbps.
32. DSL allows for the simultaneous transmission of voice data and more bandwidth-intensive multimedia
information such as Internet traffic.
33. Because DSL uses the installed base of phone lines to residences and office buildings, it is usually offered
by a local telecommunications carrier.
34. Residential users who access the Internet over cable actually share a coaxial line, meaning that transmission
speeds depend on the number of neighborhood residents who are concurrently using the service.
35. WiMAX (Worldwide Interoperability for Microwave Access) is actually another name for the IEEE 802.11
standard.
36. The function of configuration management is to track and manage all the hardware and software associated
with the computer network, and to manage any changes that occur to these architectural elements.
37. One of the most important functions of network management is security management—solving a network
outage or performance problem when it occurs.
38. Some of the security management functions for a network include network access control, user
authentication, firewall management, and critical infrastructure protection.
39. Which of the following types of networks is largest in size?
40. Which of the following is currently the largest WAN?
41. Which type of switching technique is the Internet based upon?
42. Which of the following is classified as an open protocol?
43. Which of the following is an address that is physically associated with a device such as a LAN adapter?
44. Which of the following is a device that sits between an edge router and a dedicated line such as a T-1 line?
45. Which of the following is a good alternative for transmitting sensitive information?
46. Which of the following is considered to be a disadvantage of a private network?
47. Which of the following is a technique associated with VPNs that ensures privacy and security?
48. Which of the following is a service that provides guarantees on the minimum bandwidth known as the
committed information rate (CIR) to customers?
49. Which of the following is an older WAN technology that frame relay improved upon?
50. How many bytes long is an ATM cell?
51. Which of the following is a WAN service designed to simultaneously support many types of WAN traffic, is
connection oriented and transmits data within variable length packets?
52. Which of the following supports the highest data rate?
53. Which of the following WAN access technologies connects the user to the ISP through the twisted pair
cables installed as part of the telephone network?
54. Which of the following is a type(s) of DSL technology?
55. Which of the following is a component located at the central office and used to terminate DSL connections
of subscribers?
56. What type of cable is used to provide cable modem access?
57. Which of the following is associated with the IEEE 802.16 standard?
58. Which of the following is considered an alternative to land-based WAN access options such as DSL, cable
modem access, or dedicated private lines?
59. Which of the following factors does the data rate supported by WiMax depend on?
60. Which of the following is used to track and manage all the hardware and software associated with a
computer network, and to manage any changes that occur to these architectural elements?
61. Which of the following is used to ensure that the network is performing adequately for the applications and
users it supports?
62. Which of the following is used to solve a network outage or performance problem when it occurs?
63. Which of the following is used to ensure network access control, user authentication, firewall management,
and critical infrastructure protection?
64. Which of the following is a security threat(s) to enterprise networks?
65. Wide area networking is sometimes referred to as ____________________.
66. Wide area networking developed from the way businesses first used computer networks
to exchange information internally, beginning in the mid-____________________.
67. A major advancement during the early days of wide area networking was the introduction of IBM’s
________________________________________. and Digital Equipment Corporation’s
________________________________________.
68. SNA and DECnet used ____________________ protocols, meaning that a business using IBM’s SNA could
not communicate with a business using DECnet.
69. In the packet switching approach, information sent over the Internet is broken into small segments called
____________________.
70. On the Internet, network devices called routers read the destination address and determine how to
expeditiously route packets through the networks, based on ____________________ algorithms.
71. Routers are designed to minimize ____________________, the number of times a packet traverses various
routers as it is transmitted over a network.
72. Once all the packets from a given transmission reach their destination in a computer network, they are
____________________ in their correct order.
73. The packet-switching approach of the Internet contrasts with the____________________ switching
approach of the traditional telephone network.
74. In the United States, the development of the packet-switching approach was influenced by concerns about
survivable communication networks during the ____________________.
75. ____________________ are the rules that enable information exchange over a network, including how
many bits make up a binary network address, how to place information in standard formats that anyone can
read, and rules for performing error checking over the network.
76. The dominant family of network protocols in modern architectures is ____________________.
77. ____________________ are one of the most important components in wide area networking. They are
intelligent switching devices that determine how to direct (or route) a packet across a network, based on the
packet’s destination address and network conditions.
78. The addresses that routers analyze over the Internet are called ___________________ addresses; routers
make packet forwarding decisions based on these addresses.
79. A computing device on a local area network has a ____________________ address that is physically
associated with a LAN adapter, such as an Ethernet card.
80. A router “looks up” information in a ____________________ to direct the packet in the most efficient way
toward its destination, either by sending it to another router or by leaving the packet on its current network to
route to its destination.
81. The equipment at a customer location that serves as the demarcation point between a local network and a
service provider’s WAN is often called ___________________________________.
82. If a company such as a bank wants a dedicated transmission path between its branches for private digital
communication lines, the company has the option of leasing dedicated ____________________ lines from a
network provider.
83. In contrast to dedicated private networks, the Internet is a ____________________ network shared by many
businesses and users.
84. A _________________________ is a private network arrangement that runs over a public
telecommunications network, usually the Internet.
85. Privacy and security on a VPN are achieved through the application of security measures and a technique
called ____________________
86. Through the use of ____________________ and ____________________ , a VPN that runs over the public
Internet is nearly as secure as information on private dedicated lines, and cheaper than using private networks.
87. VPN services offer ____________________ guarantees to its customers to cover such factors as latency of
packets, dropped packets that cannot be routed to their destination, and network availability.
88. VPN customers usually obtain ____________________ from the VPN provider. These contractually
guarantee that the service provider will fulfill the QoS guarantees; if not, the provider will pay penalties such as
fee reductions.
89. There are two types of software-defined paths within frame relay:
___________________________________, which are created for each information transfer and then
terminated once the information transfer is complete; and ___________________________________, which
are permanent paths that do not terminate when information transmission ceases.
90. Frame relay service providers guarantee their customers a minimum bandwidth known as the
____________________ rate.
91. Historically, frame relay originated as an improvement over an older WAN technology known as
____________________.
92. WAN service providers also offer ___________________________________, a network alternative that
93. ATM cells have a total length of ____________________ bytes:
94. ___________________________________ is a connection-oriented WAN approach; it establishes an
end-to-end virtual connection between the transmission device and destination device before transmission
begins.
95. A more practical type of WAN service, called ____________________, is designed to simultaneously
support many types of WAN traffic. In other words, this service can transport IP packets, frame relay frames,
and ATM traffic.
96. Many types of DSL technology are available, such as symmetric digital subscriber line (SDSL), asymmetric
digital subscriber line (ADSL), and _____________________________________________.
97. The quality of DSL depends on the distance between the user site and the telephone company (the “central
office”) that houses the DSL termination equipment. This equipment is known as the ____________________.
98. High-speed Internet access is also commonly provided through cable modems that connect customer
premises equipment to the Internet using existing cable television infrastructure and _____________________
cable.
99. ____________________ is actually another name for IEEE 802.16, a formal set of networking standards for
wireless metropolitan area networks developed by the Institute of Electrical and Electronics Engineers (IEEE).
100. WiMAX provides a theoretical maximum uplink and downlink speed of approximately
____________________ Mbps, although this rate can be achieved only over short ranges.
101. The function of _____________________ is to track and manage all the hardware and software associated
with the computer network, and to manage any changes that occur to these architectural elements.
102. Another function that network managers must provide is ____________________, which ensures that the
network is performing adequately for the applications and users it supports.
103. One of the most important functions of network management is ____________________—solving a
network outage or performance problem when it occurs.
104. One security threat to an enterprise network is: ____________________.
105. Explain the evolution of wide area networking.
106. Explain the concept of packet switching and how it differs from circuit switching.
107. Discuss the difference between proprietary and open protocols and give an example of each.
108. Explain the concept of Virtual Private Networking. Include a discussion of techniques and services
offered.
109. List some WAN alternatives that may be offered to subscribers through various service providers.
110. List the various types of WAN access mechanisms for connecting a local area network or an individual
handheld device or computer to a wide area network.
111. List the 3 types of DSL technologies.
112. Explain the functionality of performance management software.
113. What do those involved in security management implement and monitor and what are some security
management techniques?
