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Select a network technology: When adding to or expanding an existing network, this decision is easy - it simply requires choosing something identical to or compatible with whatever you're using. For new networks, you need to analyze what kinds of applications and services users require. For ordinary office work (e-mail, word processing, spreadsheets, basic database access, and so on) 10-Mbps Ethernet works well. For high-traffic or real-time applications - such as Computer Aided Design (CAD), imaging, video conferencing, and voice over network - 100 Mbps to the desktop makes more sense. -
Stay close to the resources: When designing a network, the smartest thing you can do is minimize the distance between users and the resources they use most. This applies to printers (so users enjoy easy access to output), servers (so cable runs needn't be too long), and other services (such as fax machines, scanners , and copiers) that users need to access to do their jobs. -
Build an online work environment: When designing a network, you also have to take into account current working patterns and arrangements in your offices. (For example, if the Accounting and Purchasing departments work together all the time, perhaps they should share a server.) This also applies to the type of network you build. For small companies, centralized control and tight security may hamper your workers; in large companies, centralized control and tight security are the norm. You must serve the communities that currently exist in your organization and use the network to help users communicate and be as productive as possible. -
Arrange servers, hubs, and other key resources: The places where wiring congregates - namely at punchdown blocks, wiring centers, and equipment rooms (or closets) - sometimes dictate where certain equipment must be placed. Be sure to check the distance between those locations and the areas where workers reside. In most cases, offices are designed to support cabling from a centrally located wiring center or equipment room for groups of offices. If that's not the case in your workspace, you may have to add new equipment rooms and wiring centers or move workers to bring them closer to existing facilities. Either of these solutions takes time and costs serious money, so be sure to get your management involved in deciding which options make the most sense and how your organization will handle these changes. -
Build better backbones: Depending on your network technology choice, you'll probably want to arrange your network to include a special highway for data to travel across when multiple network cables come together. This can happen between servers, as with the XYZ Inc. example that appears at the beginning of this chapter. Such portions of the network are called backbones. A backbone can be something as simple as a so-called collapsed backbone , in which a high-speed switch links multiple cable segments and provides a single, high-speed connection between all cable segments. A backbone can also be as complex as a staged backbone , in which intermediate segments jump from normal 10 Mbps-Ethernet to switched Ethernet or 100-Mbps Etheret at the server (as in the XYZ Inc. example mentioned at the beginning of this chapter). More complex backbones might even include a segment of Gigabit Ethernet on the innermost segment, where traffic is heaviest. -
Plan for growth: When planning a network, include at least 30 percent spare, unused capacity in your design. This spare capacity should include network ports (unused ports on hubs), unused network cables in offices and cableways, and bandwidth on individual network segments. That way, you can grow within your current environment for a while without having to redesign your network on a regular basis. If your annual growth rate exceeds 30 percent, design at least one year's planned growth into your network - better yet, one year's planned growth plus 30 percent. -
Work within the system: As you discover when you start deploying a network in any organization, networks have a political as well as a technical side. When you plan a network, you should work within your system in at least two ways: First, make sure that management knows about and approves of what you plan. Second, make sure that you handle the work, contracts, purchases, and so on within the rules and regulations of your organization. If you neglect either of these guidelines, the only thing you'll learn how to network is trouble! -
Check your design: After you put a network design down on paper, review that design against what you know about the network technologies it uses. Be especially careful to check maximum cable lengths, maximum number of devices per segment, and maximum number of cable segments and devices between any two ends of the network against the rules that apply to the technologies you plan to use. You don't want to build a network that tries to break these rules. If you do, your network may not work, or worse , it may work for a while and then quit working when you add users or devices. If you check your work before you build, you won't try to build something that can't work or that's inherently prone to trouble. -
Ask for a sanity check: After you've put a network design down on paper and checked your work, you should also solicit input from one or more networking experts. Redesigning a network is always easier while it's still on paper; you don't want to fix a flawed design after you've built a network. The more qualified advice you get before you start building, the better off you'll be in the long run. In fact, this advice is worth paying for because it can save you a world of hurt (or your job, for that matter). |
