CHAPTER 1: Network Fundamentals 36 SUMMARY OF EXAM OBJECTIVES In this chapter, we discussed the fundamentals of networking, including what defines a network, and how networks came to be. By providing an overview of these elements, we have provided a basic foundation for other topics covered throughout this book. We also looked at the various network types, topologies, and models available for a network. A network can use a centralized or distributed model, and be designed as a client/server model or peer-to-peer. In creat- ing this network, it will use one or more topologies, which is the physical layout of network components. The topologies we covered in this chapter were bus, star, ring, mesh, and wireless. Finally, the geographic scope of this network will determine what type of network you have. LANs are small networks within a limited area of a few miles, MANs are within a metro- politan area, and WANs interconnect LANs over a wide area. These char- acteristics define your network and will affect a wide variety of elements including security, media, and other features that make up your network as a whole. EXAM OBJECTIVES FAST TRACK What Is a Network? A computer network exists when two or more machines are con- nected together, thereby allowing them to share data, equipment, and other resources. An internetwork is when two or more networks are connected  together, as in the case of the Internet. A network protocol is a set of rules used to control transmission  and reception of data on a networked computer. TCP/IP is the default protocol used by the Internet and many current OSes, such as Microsoft Windows and Novell NetWare. Logical Network Topologies A centralized network model has resources and administration  that are centrally located, while a decentralized network model has resources and administration that are distributed throughout the network. Exam Objectives Fast Track 37 A peer-to-peer network model has computers on a network acting  as equals, and acting as both clients and servers of the network. When one computer requests data or other services from another computer, it acts as a client, while the other computer delivering that data or service acts as a server. A client/server network model has dedicated servers that provide  services and data to requesting computers (clients) who are autho- rized to access them. Physical Network Topologies The topology of a network is the physical layout of computers,  hubs, routers, cables, and other components. Common topologies include bus, star, ring, mesh, and wireless. All of the computers in a bus topology are connected together using  a single cable, which is called a trunk, backbone, or segment. In a star topology, computers aren’t connected to one another, but  are all connected to a central hub or switch. A mesh topology has multiple connections, making it the most  fault tolerant topology available. Ring topologies only allow one computer to have access to send  data on the ring, but provide equal access to the network. A point-to-point topology is any network that connects two hosts in  a dedicated fashion. A wireless topology broadcasts data over the air, so very few cables  are used to connect systems together. Network Types LANs are small- to medium-size networks, and generally connect  network devices that are no more than a few miles of one another. WANs can span great geographical distances, and connect different  LANs together using high-speed solutions or telephone lines. A MAN is a group of LANs that are internetworked within a local  geographic area, which the IEEE defines as being 50 km or less in diameter. CHAPTER 1: Network Fundamentals 38 EXAM OBJECTIVES FREQUENTLY ASKED QUESTIONS I am creating a home network that consists of one computer Q: running an Apple iMac and another running Windows 2000 Professional. Each of them has network adapters installed already. I want to network them together, but can’t afford much in the way of additional equipment. What kind of network should I create? Peer-to-peer. A peer-to-peer network is the simplest and least A: expensive type of network you can create. It doesn’t require a machine running more expensive server software, and can be created by configuring these machines to be networked together, and by connecting them to a hub (which is cheaper than a router) using network cabling. Being that security isn’t an issue, P2P networks are ideal in these situations. My company wants to connect the LANs of an office in one city to Q: an office in another city. They want the fastest possible connection. Which should I get? T3 lines are the fastest, but they are also the most expensive. T1 A: and T3 lines are thousands of dollars a month, and may be more than your organization needs. Before deciding on a particular con- nection for your network, try to determine what they will be using it for, how often, and how much data will be transferred from one LAN to another. What is the most fault tolerant topology available?Q: The mesh topology is the most fault tolerant, because it uses A: multiple connections to the network. In this topology every computer is connected to every other computer, so if one cable breaks, the computer can continue using the network using another connection. My company is thinking of using wireless technology, but I’ve Q: heard that hackers can access the data being transmitted using wireless. Should this be a concern? Network security should always be a concern. Data being A: transmitted using wireless technology can be protected using data encryption methods, which can prevent unwanted individuals from being able to decipher the data they capture from wireless signals. Self Test 39 What is the need for standards in networking?Q: Standards provide common methods and criteria for designing, A: developing, and manufacturing the hardware and software used in networks. It allows different devices to communicate with one another, regardless of who manufactured them, so that networks aren’t limited to using proprietary equipment. It also provides best practices, recommendations, and information that is necessary to network communication (such as protocols that allow devices to transfer data). SELF TEST You are creating a network for a small business with only four 1. employees. Because employees often leave the office to visit clients, a minimum of one person is in the office and using a computer at any given time. Currently there are two computers in the office, but the company is willing to purchase more if needed. Based on this information, what is the minimum number of computers that you’ll need to create a network? A. One B. Two C. Three D. Four A new intranet has been created in your organization, and includes 2. an FTP site to download files and a news server for sharing infor- mation. The network is internetworked with a network belonging to a subsidiary of the company. The subsidiary’s network uses Apple computers, and uses AppleTalk as a network protocol. To access the intranet, which of the following protocols would need to be installed on your computer? A. IPX/SPX B. NWLink C. TCP/IP D. AppleTalk The LAN used by your organization is on the single floor of a 3. building. The network has servers and other resources that are kept in a secure server room. You are the only network administrator CHAPTER 1: Network Fundamentals 40 in the organization and have sole responsibility of managing these resources and administration of network security for all of the users who are distributed throughout the network. What type of network model is being used? A. Centralized B. Decentralized C. Distributed D. Peer-to-Peer Your company’s network is on several floors of a building. Because of 4. the amount of data being stored, there are three file servers, a Web server for the intranet, an e-mail server for internal e-mail, and a SQL server that is used for several databases that have been developed in house. Because of security reasons, floppy disks and other devices to transfer or transmit data to and from the computer have been removed and aren’t permitted. What type of network model is being used? A. Client/Server B. Peer-to-Peer C. MAN D. PAN Your company’s network spans three buildings that are within a mile 5. of one another. Three servers are kept in a secure server room in the building where your office is located, while each other building has a server that is locked in a closet. Users at each of these locations have been trained on how to replace the backup tapes in these servers and have the ability to give permissions for user accounts to print to specific printers in those locations. You solely control other aspects of security, inclusive to password requirements, and access to folders on these servers. What type of network model is being used? A. Centralized B. Decentralized C. P2P D. Peer-to-Peer A company has hired you to create a network for their small busi-6. ness. Security isn’t an issue, and there isn’t enough money to hire or train a permanent network administrator. Users of the network routinely work on similar projects, and need to access one another’s data on a regular basis. What type of network model will you use? Self Test 41 A. Client/Server B. Peer-to-Peer C. Client D. Server A company has multiple offices that are internetworked. Office A 7. has a single computer that has the ability to dial into the Internet, but isn’t connected to the other offices. Office B is in another part of the country from the other offices, but doesn’t have its network interconnected to the other offices. Office C and D are in separate states, but have a dedicated connection between them. Office C has 20 computers that access each other’s machines, and provide services and data to one another. Office D has 50 computers that log onto the network using a single server. Based on this information, which of the Offices are part of a LAN and a WAN? A. Office A and B B. Office B and C C. Office C and D D. The entire network (Office A, B, C, and D) An organization has offices in two countries. Office A is a small 8. field office with two networked computers and is internetworked with Office B that is across the road and has 10 networked computers. Because they are a subsidiary of the main company and perform different services from the rest of the organiza- tion, neither of these offices have been internetworked with the other offices, and is awaiting Internet connectivity to be provided next month. Office C is another field office that has a single computer, isn’t networked with other offices, and only has an Internet connection. Office D is the headquarters of the company, has 100 network users who are awaiting Internet connectivity to be added to the network, and has a network connection to Office E in London, which is their European office. Based on this information, which of the offices is connected to the largest WAN? A. Office A B. Office B C. Office C D. Office D CHAPTER 1: Network Fundamentals 42 A company wants to create a LAN between two networks in 9. different cities. To connect them, you want to have the fastest possible connection to meet their needs. Each network has mas- sive amounts of data being sent between floors of their existing networked building, and you determine that at maximum, 1 Mbps of data will need to be transmitted during normal business hours. Although they are a large business, and cost is not a major issue, they don’t want to waste money on getting a solution with a band- width that’s higher than they need. What type of connection will you choose in connecting these networks? A. Dial-up modem B. ISDN C. T1 D. T3 A company has several offices that are networked together across 10. the city. Each of the sales representatives uses PDAs to keep track of appointments with clients. The company has just implemented a new system where the appointments taken by receptionists are automatically uploaded to the PDAs whenever the sales staff enters the main reception area. What types of networks are being used in this environment? Choose all that apply. A. MAN B. SAN C. CAN D. PAN You have been hired by a company that uses a topology shown in 11. Figure 1.8. In looking at the physical layout of your network, which of the following types of topologies is being used? A. Bus B. Star C. Mesh D. Ring FIGURE 1.8 Self Test 43 You receive a call that the network is down. In this network, all 12. of the computers are connected together using a single cable, which they are connected to using T-Connectors. Looking at the situation, you find that there is no break through the trunk. Which of the following is most likely the cause of the problem? A. A failed network card. B. One of the computers is turned off. C. T-connectors are missing from the ends of the cable. D. Terminators are missing from the ends of the cable. Your network uses cells to send and receive data to and from com-13. puters. This allows computers in different buildings to be networked together, so they can access data from servers in either building. A topology map has been created, using circles to identify the areas that computers can be placed to access the network. Based on this information, which of the following topologies is being used? A. Star B. Mesh C. Wireless D. Ring You are training a new member of the IT Staff, and decide to 14. explain the topology of the existing network, shown in the Figure 1.9. What topology is currently being used? A. Bus B. Star C. Mesh D. Ring FIGURE 1.9 CHAPTER 1: Network Fundamentals 44 Your network has 10 computers that are networked together using 15. a star topology. Which of the following is a possible point of failure for this topology, which could bring down the entire network? A. Cable B. Network card C. T-Connector D. Hub SELF TEST QUICK ANSWER KEY B1. C2. A3. A4. B5. B6. C7. C8. C9. A and D10. A11. D12. C13. C14. D15. 45 EXAM OBJECTIVES IN THIS CHAPTER CABLING AND CONNECTORS OVERVIEW 46 MEDIA ISSUES 49 CABLE TESTERS AND TROUBLESHOOTING 58 SIMPLEX, HALF-DUPLEX, AND FULL-DUPLEX 63 CABLING 63 CABLE MANAGEMENT 67 LAN TECHNOLOGIES AND STANDARDS 69 CONNECTORS 75 OTHER MEDIA 85 INTRODUCTION In this chapter, we’ll take a look at what you will need to know about cable connections and termination for the Network exam. When working in the field of networking, it’s nearly impossible to not come across physical cabling. Unless you have wireless media (covered in Chapter 4), you will need some form of cabling, and need some form of endpoint, or termina- tion, to your transmission media and a way for it to physically connect to a device. This endpoint is called a connector, and it terminates the end of the media, creating a way for it to connect to something else such as a patch panel, switch port, or other connection. This chapter shows you what you need to know about connecting and terminating the most common forms of cable in use today: twisted-pair cabling, coaxial cabling, and fiber optics. The understanding of transmission media types, connectors, and termination is essential to being a networking professional. In this chapter, we will learn the fundamentals of cabling, the connectors used with them, and the most common tools of the trade. CHAPTER 2 Network Media . TESTERS AND TROUBLESHOOTING 58 SIMPLEX, HALF-DUPLEX, AND FULL-DUPLEX 63 CABLING 63 CABLE MANAGEMENT 67 LAN TECHNOLOGIES AND STANDARDS 69 CONNECTORS 75 OTHER MEDIA 85 INTRODUCTION In this chapter, we’ll. ANSWER KEY B1. C2. A3. A4. B5. B6. C7. C8. C9. A and D10. A11. D12. C13. C14. D15. 45 EXAM OBJECTIVES IN THIS CHAPTER CABLING AND CONNECTORS OVERVIEW 46 MEDIA ISSUES 49 CABLE TESTERS. Decentralized C. P2P D. Peer-to-Peer A company has hired you to create a network for their small busi -6. ness. Security isn’t an issue, and there isn’t enough money to hire or train a permanent network