Networking: A Beginner’s Guide Fifth Edition- P45 doc

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Networking: A Beginner’s Guide Fifth Edition- P45 doc

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202 Networking: A Beginner’s Guide N Is the vendor sufficiently successful and stable that you can expect the company to be around for the entire useful life of the unit? N What other value-added services are offered if problems occur? Other factors that strongly influence serviceability are often overlooked. How many computers does the maker sell, and is the specific model that you are buying widely used? These factors are important because a widely used computer is more likely to be supported when new software or hardware comes out. Companies that make software and hardware know they must ensure that their products work properly with popular computer brands and models. Suppose that you use computers from a small, local company (or, even worse, build the computers yourself), and some software package or operating system that comes out in a year or two fails to work properly on your machines. The maker of the software or hardware might say something like, “Well, we haven’t tested on that computer, so we don’t know why our product isn’t working right.” While the maker might act in good faith to resolve the issue, the problem might take much longer to fix on a widely used system, and it might never be resolved. On the other hand, if you’re using a top-tier computer, such as one from Compaq, Dell, or HP (or other top-tier brands), the vendor of the new product probably knows how to resolve any problems that arise and has already done so before the product was shipped. TIP If your company runs an application that is vital to its business but that is not widely used, it sometimes pays to find out which computers the application maker uses. If you know that the application maker has built the application using a particular make, you can reduce your risk of having trouble with that application by considering using the same brand in your organization. Author’s Note I once joined a company that had been purchasing “no-name” clones for its desktop computers. In my first week, I set up five brand-new units right out of their boxes, only to find that three of them were dead on arrival (DOA). That same week, the company’s CFO, who was working on an important financing activity, had his computer crash repeatedly (losing unsaved work each time), until I finally swapped his entire computer for one of the new ones that actually worked. Was the money saved on those computers (about $400 per unit) worth it? What was the cost to the company for all these mishaps? The answer is simple: far more than the company saved. I immediately changed the company’s brand to a more reliable one (the CFO was sympathetic!) and got rid of the existing machines as quickly as possible. The lesson is that you shouldn’t be penny-wise and pound-foolish when you purchase computers. 203 Chapter 14: Purchasing and Managing Client Computers You can also improve serviceability if you standardize on a particular manufacturer because then you can focus your resources on supporting that line of computers. The people who support the desktop computers in the company will find it easier to stay up-to-date with the peculiarities of that manufacturer and will become more comfortable working with those computers. Also, your company’s support staff will be able to solve a problem once and then apply the solution to many computers, rather than having to troubleshoot many different types of problems on many different types of computers. Finally, there might be service-quality benefits when you establish a strong, ongoing relationship with a computer manufacturer. NOTE If you support many computers, make sure that they are as consistent as possible. Not only do you want to ensure (as much as possible) that they are the same model and the same configuration, you also want to make sure the manufacturer uses the same components for all computers of a particular model. Some manufacturers are not careful about this; they will slip in different motherboards or network interface cards (NICs) without any notice. For someone buying a single computer, this isn’t a problem. When you need to support 500 or 5,000 computers that are all supposed to be exactly the same but aren’t, it becomes a huge problem, because then you also must keep track of different drivers and configuration information. Also, if you install and maintain computers through the use of disk images (such as those made by Norton Ghost), you will need to maintain different images for all of the different submodels of the computer. Price and Performance Once the preceding priorities are satisfied, you can then strike the appropriate balance between performance and price. You need to take into account the useful life that you plan for new computers and make certain to purchase systems that will be productive over that useful life. In determining this balance, don’t look at how well a particular configuration can handle today’s needs; look at how well it can handle tomorrow’s needs. Some people might disagree, but I firmly believe that price should be your last priority when you purchase computers. Although purchase price is important, you first need to determine your needs and then find the most reasonably priced computers that best fulfill those needs. Different strategies exist for getting the best price. These strategies range from straightforward bargaining and competitive bids, to slightly under-purchasing on the performance side but planning to upgrade the existing computers when needed (at least in terms of RAM and hard disk space, both of which decrease pretty rapidly in price over time). NOTE Don’t forget to estimate the cost involved to replace a computer or to upgrade a computer when you choose a system. It might be less expensive overall to purchase a more capable computer that you won’t need to upgrade or replace as quickly, when you factor in the labor costs and user productivity impact from installing a replacement. 204 Networking: A Beginner’s Guide As a rule of thumb, you can estimate that the demands placed on a desktop computer will double every 24 months or so, taking into account your planned useful life. Set your performance levels to meet that need. (People used to assume performance requirements doubled every 18 months, but this seems to be slowing a bit in recent years.) For example, suppose that you’ve determined that today’s user requires 40GB of disk space, 2GB of RAM, and a Pentium 2.8 GHz processor. In 24 months, your users are likely to be clamoring for 80GB of disk space, 4GB of RAM, and a Pentium quad-core 3 GHz processor. In another 24 months (about four years from purchase), these demands will double again, to 160GB of disk space, 8GB of RAM, and the equivalent of a Pentium 8-core processor. These projected demands might seem unlikely today, but when you look back at the needs of four years ago, such projections seem reasonable. Using this way of estimating performance needs, you should be able to find a “sweet spot” between price, performance, and useful life that minimizes your costs and maximizes the benefits that your users will receive. Understanding Network Workstation Requirements Computers connected to a local area network (LAN) differ slightly from computers that stand alone. They have additional hardware installed in them, and they run additional network software. This section explores these differences. Network Workstation Hardware All network computers need an installed network interface to connect to the network. Generally, most desktop computers these days have an intergrated Ethernet network interface built-into them. And if a computer does not, then it can be added as a network interface card. NICs are also usually specific to the cable media you have installed. For example, Ethernet NICs are available for 10Base-2, 10Base-T, 100Base-T, and 1000Base-T media. DEFINE-IT! Useful Life The term useful life refers to the length of time a particular asset, such as a computer, will be able to perform useful work. The useful life of a computer will change depending on the computer, the software it needs to run, the user who uses it, and the budget available to upgrade or replace it. A programmer who needs the latest and greatest hardware and software all the time will get a relatively short useful life out of a computer, while a person who uses a computer only for word processing or e-mail and doesn’t care about running the latest software will get a much longer useful life out of a computer. For most desktop computers, the useful life is around three to four years, although exceptions to this rule of thumb are easy to find. 205 Chapter 14: Purchasing and Managing Client Computers Some NICs also support multiple media types, which can be a blessing if you’re in the middle of migrating from one media type to another. For example, a single Ethernet NIC may support 10Base-2, 10Base-T, and 100Base-T. At the time of this edition’s writing, most business computers come with integrated Ethernet ports capable of 100Base-T or 1000Base-T. Network Workstation Software Network workstations also need networking software to work with the network. This software consists of several components: a driver for the NIC, driver software for the protocols being used, and a network requestor (sometimes called a network redirector). Workstations acting in a peer-to-peer fashion also have peer software that provides network services to other workstations. Additionally, network service software might be needed, such as that required to use a particular network directory service (for example, Novell’s eDirectory). For Windows-based computers, you can choose to use software that is included with Windows to connect to both Novell networks and to Windows-based networks. You can also use Novell’s network software for Novell-based networks. Both sets of network software work well, although differences exist. For Novell-based networks, Microsoft’s networking software consumes less memory than Novell’s, but it doesn’t offer as many features and doesn’t integrate with the Novell servers quite as well. Still, it’s reliable and performs well. Novell’s client software (called Novell Client) works well and makes good use of the Novell server’s features, and is also more secure than Microsoft’s Novell network software. When using the Microsoft software with NetWare 4.x or later servers, you must also run service software to access Novell’s directory service. This software is included both with Windows and Novell Client. Under Windows, you manage the network software through the network Properties dialog box for Network Neighborhood or through the Network object in the Control Panel (which also accesses the network Properties dialog box). Figure 14-1 shows an example of this dialog box. The network Properties dialog box contains a number of entries, including the following main categories: N Client You might have client software installed for Novell networks or Microsoft networks. This client software interacts with the servers to request network services. In Figure 14-1, you can see that the Client for Microsoft Networks is an installed component. N Network interface This entry represents the driver software that is installed for any installed NICs or for “virtual NICs” used to connect to a network through a modem. In Figure 14-1, you can see the NVIDIA nForce driver listed. N Protocols This software adds support for any needed networking protocols, such as TCP/IP, IPX/SPX, or NetBEUI. N Services Any additional network service software, such as that used for Novell eDirectory, also appears in the network Properties dialog box. 206 Networking: A Beginner’s Guide NOTE For many networking components, you may need to have a the component available from the appropriate supplier. Chapter Summary Managing network workstation computers can be a daunting task. Many of them must be managed frequently, each user may have different needs, and because of how they are used, network workstation computers are the most likely to experience trouble. In this chapter, you learned general information about network client computers, along with how to select appropriate client computers for your network. You also learned about the components that network computers have in common, which separate them from stand-alone desktop computers. In the next chapter, you learn about the basics of how you can design a network from the ground up. Generally, the process of network design is to first thoroughly understand the needs that the network must meet, factor in anticipated growth for the network, and then start to lay out how the network will be structured and which technologies will be needed. Figure 14-1. The network Properties dialog box in Windows Vista . them. And if a computer does not, then it can be added as a network interface card. NICs are also usually specific to the cable media you have installed. For example, Ethernet NICs are available. connected to a local area network (LAN) differ slightly from computers that stand alone. They have additional hardware installed in them, and they run additional network software. This section. sometimes pays to find out which computers the application maker uses. If you know that the application maker has built the application using a particular make, you can reduce your risk of having

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Mục lục

  • Contents

  • Acknowledgments

  • Introduction

  • Part I: Networking Ins and Outs

    • 1 The Business of Networking

      • Understanding Networking: The Corporate Perspective

      • Understanding Networking Jobs

      • Sarbanes-Oxley Act of 2002

      • Chapter Summary

      • 2 Laying the Foundation

        • Bits, Nibbles, and Bytes

        • Basic Terminology to Describe Networking Speeds

        • Chapter Summary

        • 3 Understanding Networking

          • Knowing Network Relationship Types

          • Learning Network Features

          • Understanding the OSI Networking Model

          • Learning About Network Hardware Components

          • Chapter Summary

          • 4 Understanding Network Cabling

            • Understanding Cable Topologies

            • Demystifying Network Cabling

            • Installing and Maintaining Network Cabling

            • Chapter Summary

            • 5 Home Networking

              • Benefits from Home Networking

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