Installing New Cabling Cabling

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3.1.1 Installing New Cabling

If you are faced with a new installation, take the time to be sure it is done correctly from the start. While it is fairly straightforward to wire a few machines together in a home office, cabling should not generally be viewed as a do-it-yourself job. Large cabling projects should be left to trained professionals whenever possible. Cabling is usually a large investment. Correcting cabling problems can be very costly in lost time both for diagnosing the problem and for correcting the problem. Also, cabling must conform to all applicable building and fire codes. For example, using nonplenum cabling in plenum spaces can, in the event of a fire, greatly endanger the safety of you and your fellow workers. Plenum cabling is cabling designed to be used in plenum spaces, spaces used to recirculate air in a building. It uses materials that have low flame-spread and low smoke-producing properties. Cabling can also be very sensitive to its physical environment. Cable that runs too near fluorescent lights or large motors, e.g., elevator motors, can be problematic. Proximity to power lines can also cause problems. The network cable acts like an antenna, picking up other nearby electrical activity and introducing unwanted signals or noise onto the network. This can be highly intermittent and very difficult to identify. Concerns such as these should be enough to discourage you from doing the job yourself unless you are very familiar with the task. Unfortunately, sometimes budget or organizational policies are such that you will have no choice but to do the job yourself or use internal personnel. If you must do the job yourself, take the time to learn the necessary skills before you begin. Get formal training if at all possible. Invest in the appropriate tools and test equipment to do the job correctly. And make sure you arent violating any building or fire codes. If the wiring is handled by others, you will need to evaluate whether those charged with the task really have the skill to complete the job. Most electricians and telephone technicians are not familiar with data cabling practices. Worse still, many dont realize this. So, if asked, they will reassure you they can do the job. If possible, use an installer who has been certified in data cabling. Once you have identified a likely candidate, follow up on her references. Ask for the names of some past customers and call those customers. If possible, ask to see some of her work. When planning a project, you should install extra cable whenever feasible. It is much cheaper to pull extra cable as you go than to go back and install new cable or replace a faulty cable. You should also consider technologies that will support higher speeds than you are currently using. For example, if you are using 10-Mbps Ethernet to the desktop, you should install cable that will support 100 Mbps. In the past it has been a common recommendation to install fiber-optic cables to the desk as well, even if you arent using fiber technologies at the desk at this time. Recent developments with copper cables have made this more of a judgment call. Certainly, you will want to pull spare fiber to any point your backbone may eventually include. If at all feasible, cabling should be certified. This means that each cable is tested to ensure that it meets appropriate performance standards for the intended application. This can be particularly important for spare cabling. When it is time to use that cable, you dont want any nasty surprises. Adequate documentation is essential. Maintenance will be much simpler if you follow cabling standards and use one of the more common structured cable schemes. More information can be found in the sources given in Appendix B . 37

3.1.2 Maintaining Existing Cabling