COMPUTERS ARE YOUR FUTURE
CHAPTER 7
NETWORKS: COMMUNICATING AND
SHARING RESOURCES
Answers to End-of-Chapter Questions
Matching
__g___1. router “Network Fundamentals” __o___2. node “Network Fundamentals” __i___3. ring “LAN Topologies” __l___4. hub “Network Fundamentals” __c___5. star “LAN Technologies” __n___6. backbone “Backbones”
__b___7. latency “Circuit and Packet Switching” __a___8. switch “Network Fundamentals” __m___9. bus “LAN Topologies” __e___10. protocol “LAN Protocols”
__f___11. logical address “Network Fundamentals” __k___12. physical addres “Network Fundamentals” __d___13. topology “LAN Topologies” __j___14. contention “LAN Topologies”
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 2
Multiple Choice
1. Which is an advantage of networking? a. Increased hardware costs
b. Increased autonomy
c. Centralized data management “Advantages and
Disadvantages of Networking”
d. Increased privacy of network members
2. What is the acronym for a computer network within a single residence?
a. WAN
b. PAN
c. HAN “Home Networks?
d. CAN
3. Which is a type of network topology? a. client/server
b. star “LAN Topologies”
c. P2P d. WAN
4. A ___________ is necessary to make the connection between a local area network and the Internet?
a. hub b. switch
c. router “Home Ethernet Network”
d. POP
5. Which of the following statements about peer-to-peer networks is true? a. They require at least one router.
b. They require at least one server.
c. They require a network operating sytem.
d. They perform best when connecting 10 or fewer computers. “Peer-to-Peer Networks” 6. Encryption on a wireless network is activated by enabling _____________.
a.WPA “WiFi”
b. NOS
c. WEP d. NIC
7. Which is not a hardware device used to attach a device to a wireless network? a. PC card
b. NIC “Wireless Home Networks”
d. PCI card
8. Which of the following is a common contention-management technique?
a. abandoning data corrupted by a collision “LAN Topologies” b. retransmitting unreceived packets
c. generating a new token
d. adding terminators to minimize signal loss 9. Which is a feature of packet switching?
a. There is a direct connection between the communicating devices. b. All packets of a message are sent and received in order.
c. Packets of a message are split up and reassembled at the destination device. “Circuit
and Packet Switching”
d. All packets travel on the same path to the destination.
10. A(n) _____________ is a network device with software that manages network resources like files, e-mails, printers, and databases.
a. client
b. server “Network Fundamentals”
c. firewall d. switch
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 4
Fill-In
1. A(n) _____________ is assigned to every computer on the Internet to facilitate the exchange of data.
Internet address “WAN Protocols”
2. A(n) _____________ is a wired or wireless WAN network connection point that enables users to access the WAN.
point of presence (POP) “Point of Presence”
3. A network model that does not require a network operating system is called a _____________ network.
peer-to-peer “Peer-to-Peer Networks?
4. A(n) _____________ is a computer professional that installs, maintains, and supports computer networks.
network administrator “Network Fundamentals” 5. A wireless LAN uses _____________ instead of wires to transmit data.
radio waves “Local Area Networks”
6. A(n) _____________ is node on a network that acts as a receiver and transmitter of wireless radio signals between other nodes on a network.
wireless access point “Network Fundamentals”
7. A(n) _____________ operates as a private network that runs over a public network, usually the Internet.
virtual private network “Virtual Private Networks (VPN)” 8. The _____________ is the largest WAN.
Internet “Wide Area Networks” 9. A public wireless access location as known as a(n) _____________.
hot spot “LAN Protocols” 10. Data in a ring topology is referred to as a(n) _____________.
token “LAN Topologies”
11. _____________ is the communication method used in the public telephone system, where a direct connection exists between communicating devices.
Circuit switching “Circuit and Packet Switching”
12. A(n) _____________ is a computer network that is limited to a college campus or business park.
13. A(n) _____________ is a password-protected network controlled by the company and accessed only by employees.
intranet “Virtual Private Network (VPN)” 14. The _____________ network topology makes use of a token.
ring “LAN Topologies”
15. _____________ is the collection of open protocols that define how the Internet works.
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall 6
Short Answer
1. List at least two benefits of a wired network and two benefits of a wireless network.
A wired network is the network of choice for online gamers and those that transfer large files where speed is a priority.
Wireless networks are gaining in popularity because of their ease of setup and convenience. There are no unsightly wires to run, and users are no longer limited to working in just one location.
2. How do LANs, WANs, and HANs differ?
LANs and WANs have the same basic network components—cabling, protocols, and devices—for routing information to the correct destination. A LAN is a network within a small geographic area, like a college campus.
A WAN is a network that covers larger geographic areas, such as cities and states. A WAN can be considered a LAN that has long-distance communication needs among its servers, computers, and peripherals. The largest WAN is the Internet.
A HAN, on the other hand, is a computer network within a single residence or home.
3. What is the difference between circuit switching and packet switching?
With circuit switching, the method used in the public switched telephone system, there is a direct connection between the communicating devices. Data is sent over a physical end-to-end circuit between the sending and receiving computers.
With packet switching, the method used for computer communication, no effort is made to create a single direct connection between the two communicating devices. The
sending computer’s outgoing message is divided into packets. Each packet is numbered and addressed to the destination computer. The packets then travel to a router, which examines each packet it detects. After reading the packet’s address, the router consults a table of possible pathways that the packet can take to get to its destination. If more than one path exists, the router sends the packet along the path with the least
congestion. The packets may not all take the same path or arrive in the order they were sent, but that’s not a problem. On the receiving computer, protocols put the packets in the correct order and decode the message they contain. If any packets are missing, the receiving computer sends a message requesting retransmission of the missing packet.
4. Name three types of LAN topologies and describe how each works.
1. For a bus topology, the network cable is a single conduit that forms a bus, or line; every node, whether a computer or peripheral device, is attached to that bus. At the ends of the bus, special connectors, called terminators, signify the end of the circuit. With a bus topology, only one node can transmit at a time. If more than one node tries to send data at the same time, each node waits a short, random amount of time and then attempts to retransmit the data. The bus topology is practical in a
relatively small environment such as a home or small office.
2. For a star topology, a central wiring device is used, which can be a hub, switch, or computer. Adding users is simple; you just run a cable to the hub or switch and plug the new user into a vacant connector. Star networks also generally use contention management to deal with collisions. The star topology is ideal for office buildings, computer labs, and WANs. The downside of a star topology is that the loss of the hub, switch, or central computer caused by a power outage or virus invasion can bring down the entire network.
3. With a ring topology, all the nodes are attached in a circular wiring arrangement. This topology, not in common use today, provides a unique way to prevent
collisions. A special unit of data, called a token, travels around the ring. A node can transmit only when it possesses the token. Although ring networks are circular in that the token travels a circular path, they look more like star networks because all the wiring is routed to a central switch. The ring topology is well suited for use within a division of a company or on one floor of a multifloor office building.
5. List four precautions you can take to protect a home network from failure or infection by malware.
Use virus protection software. Use a firewall.
Don’t open e-mails from unknown senders. Don’t run programs of unknown origin. Disable hidden file name extensions.
Keep all applications and your operating system updated. Turn off your computer when not in use.
Disable Java, JavaScript, and ActiveX, if possible. Disable scripting features in e-mail programs. Make regular backups.
