What is guaranteed performance? After installation, it makes all the difference - Guest Column

Communications News, Sept, 2002 by Andre Mouton

Networks are crucial to modern enterprise. The structured cabling system, though it may represent only 20% of network investment, may account for up to 80% of network efficiency. Compared to the five-year average lifespan of active equipment, the 10- to 20-year lifespan of structured cabling systems means a weak system will command company operations far into the future.

If the structured cabling system is strong, providing high performance and designed to handle future needs, it will be transparent--no one will notice it. If the structured cabling system is weak, the network will under-perform and fail to give targeted data throughput; costly reworking of the whole building's cabling infrastructure may be required when introducing the next generation of active equipment.

With so many companies and technologies involved, IEEE developed minimum required performance levels for each network component, in order to ensure overall network performance. The minimum required performance for structured cabling has been developed by the Telecommunications Industry Association.

A "just-standard-compliant" system will have limitations, since standards requirements lag behind technology advancements and represent the minimum requirements the industry can or must provide. Major manufacturers, however, provide structured cabling solutions that exhibit performance well beyond standards. Cutting-edge technology requires performance beyond standards.

Care should be given when comparing system performance. All manufactured products have variations, and these variations induce variations in the product characteristics. For example, if the volume of water inside several purchased 10 separate liters of bottled water is precisely measured, one bottle might contain 1.05 liters, another 1.01 liters. Statistically, 1.01 would be the minimum value, 1.05 the maximum value and, maybe, 1.04 the average value for the 10 bottles.

High-performance structured cabling systems are sensitive to the following variables:

Component performance. Channel performance derives from each component's performance: the cable and all connectivity components must be optimized. To offer the best solution, each component must exhibit high performance.

Matching components. Component matching allows achievement of optimum channel performance. For example, the choice of matched patch cords allows full advantage of a jack's high transmission characteristics. By using unmatched components, one obtains "just-standard-compliant" performance.

One manufacturer for all components. To achieve a finely tuned, optimized structured cabling solution, choose a manufacturer that has complete control over cable and connectivity component design and production. This will ensure outstanding results, and one source for technical support.

Quality installation. Craftsmanship is critical to Category 6 systems. Installers must be well trained and certified. Only a few companies have stringent policies for selecting and training installers. The only reliable performance rating is guaranteed performance: end-users need to know what their on-site system performance will be, not the system performance measured in laboratories under ideal conditions. The only way an end-user can be assured of a specific level of on-site performance is to obtain an on-site performance guarantee from the manufacturer.

A built-in performance margin in the structured cabling system will accommodate system variances caused by installation or environmental factors, and will support tomorrow's active equipment needs. Typical, average or possible values under ideal conditions are not what counts--guaranteed channel performance after installation makes the difference. Channel performance takes into account all system components and identifies any weak links due to installation or design.

Checklist

Before comparing any performance numbers ask the following questions to compare channel performance:

* Are the performance numbers guaranteed values or nonguaranteed values?

* Are guaranteed values clearly stated in the certification or warranty documentation?

* What restrictions limit the guaranteed values?

* Are all channel components optimized? Does the same company manufacture them?

* What policies does the manufacturer have in place to ensure that system installers are properly trained and certified?

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Mouton is manager, copper products line, at NORDX/CDT, Quebec, Canada.