The Golden Rules of Data Cabling,The Importance of Reliable Cabling,The Legacy of Proprietary Cabling Systems, Cabling and the Need for Speed, Cable Design , Data Communications 101, Speed Bumps: What Slows Down Your Data, The Future of Cabling Performance. Learn how to Cabling, Know that better than the best.
“Data cabling! It’s just wire. What is there to plan?” the newly promoted programmer turned MIS-director commented to Jim. The MIS director had been contracted to help the company move its 750-node network to a new location. During the initial conversation, the director had a couple of other “insights”:
●He said that the walls were not even up in the new location, so it was too early to be talking about data cabling.
●To save money, he wanted to pull the old Category 3 cabling and move it to the new location. (“We can run 100Base-TX on the old cable.”)
●He said not to worry about the voice cabling and the cabling for the photocopier tracking system; someone else would coordinate that. Jim shouldn’t have been too surprised by the ridiculous nature of these comments. Too few people understand the importance of a reliable, standards-based, flexible cabling system. Fewer still understand the challenges of building a high-speed network. Some of the technical problems associated with building a cabling system to support a high-speed network are comprehended only by electrical engineers. And many believe that a separate type of cable should be in the wall for each application (PCs, printers, terminals, copiers, etc.). Data cabling has come a long way in the past 20 years. This chapter discusses some of the basics of data cabling, including topics such as:
●The golden rules of data cabling
●The importance of reliable cabling
●The legacy of proprietary cabling systems
●The increasing demands on data cabling to support higher speeds
●Cable design and materials used to make cables
●Types of communications media
●Limitations that cabling imposes on higher-speed communications
●The future of cabling performance
You are probably thinking right now that all you really want to know is how to install cable to support a few 10Base-T workstations. Words and phrases such as attenuation,crosstalk,twisted pair,modular connectors, and multi-mode optical-fiber cable may be completely foreign to you. Just as the world of PC LAN's and WANs has its own industry buzzwords, so does the cabling business. In fact, you may hear such an endless stream of buzzwords and foreign terminology that you’ll wish you had majored in electrical engineering in college. But it’s not really that mysterious and, armed with the background and information we’ll provide, you’ll soon be using cable speak like a cabling professional.
The Golden Rules of Data Cabling
Listing our own golden rules of data cabling is a great way to start this chapter and the book. If your cabling is not designed and installed properly, you will have problems that you can’t even imagine. From our experience, we’ve become cabling evangelists, spreading the good news of proper cabling. What follows is our list of rules to consider when planning structuredcabling systems:
●Networks never get smaller or less complicated.
●Build one cabling system that will accommodate voice and data.
●Always install more cabling than you currently require. Those extra outlets will come in
●Use structured-cabling standards when building a new cabling system. Avoid anything
●Quality counts! Use high-quality cabling and cabling components. Cabling is the foundation of your network; if the cabling fails, nothing else will matter. For a given grade or category of cabling, you’ll see a range of pricing, but the highest prices don’t necessarily mean the highest quality. Buy based on the manufacturer’s reputation and proven performance, not the price.
●Don’t scrimp on installation costs. Even quality components and cable must be installed correctly; poor workmanship has trashed more than one cabling installation.
●Plan for higher speed technologies than are commonly available today. Just because 1000Base-T Ethernet seems unnecessary today does not mean it won’t be a requirement in five years.
●Documentation, although dull, is a necessary evil that should be taken care of while you’re setting up the cabling system. If you wait, more pressing concerns may cause you to ignore it.
The Importance of Reliable Cabling
We cannot stress enough the importance of reliable cabling. Two recent studies vindicated our evangelical approach to data cabling. The studies showed:
●Data cabling typically accounts for less than 10 percent of the total cost of the network infrastructure.
●The life span of the typical cabling system is upwards of 16 years. Cabling is likely the second most long-lived asset you have (the first being the shell of the building).
●Nearly 70 percent of all network-related problems are due to poor cabling techniques and cable-component problems.
Of course, these were facts that we already knew from our own experiences. We have spent countless hours troubleshooting cabling systems that were nonstandard, badly designed, poorly documented, and shoddily installed. We have seen many dollars wasted on the installation of additional cabling and cabling infrastructure support that should have been part of the original installation. Regardless of how you look at it, cabling is the foundation of your network. It must be reliable!
The Cost of Poor Cabling
The costs that result from poorly planned and poorly implemented cabling systems can be staggering. One company that had recently moved into a new office space used the existing cabling, which was supposed to be Category 5 cable. Almost immediately, 100Mbps Ethernet network users reported intermittent problems.
These problems included exceptionally slow access times when reading e–mail, saving documents, and using the sales database. Other users reported that applications running under Windows 98 and Windows NT were locking up, which often caused them to have to reboot their PC. After many months of network annoyances, the company finally had the cable runs tested. Many cables did not even meet the minimum requirements of a Category 5 installation, and other cabling runs were installed and terminated poorly.