When selecting structured cabling vendors, one of the most difficult tasks is sorting through the vendor-provided data and getting to the information most critical to you and your network. In that stack of marketing materials, you should immediately look not only for test reports, but also details of the vendor’s contractor training program, available support services and warranty claims.
If you can easily get that information from a vendor, you’re off to a good start. But now the homework begins – is the documentation worth the paper (or web page) it is printed on? Here are a few things you should look for.
The Process
When the structured cabling vendors selection process starts, many companies look first and solely to independent test reports. Test results can be promoted as either worst case or typical. It is important to know which type of results are represented by the report, as worst case and typical should never be compared as equivalent values. If all vendors under consideration are reporting worst-case results, it is then important to look at the test parameters to determine which will provide a better system.
The same holds true for typical results. Although typical reports will provide more variable performance data, it is more important to compare solutions on an even playing field. That said, if a company has not provided the report (either best case or typical) you need for a fair comparison, ask for it. Most vendors should be able to provide both typical and worst case data.
Variables
Once you have established the type of report, it is critical to remember that seemingly similar results may not have been gained under “apples to apples” test criteria. While independent testing goes a long way to ensure validity of performance claims and can offer a degree of structure to the testing parameters, it leaves some holes. For instance, channels can provide different results based on test unit launch cords, lengths and other variables.
A 100m channel can consist of an 80m cable with two 10m cables or a 90m channel with two 5m patch cords. You cannot compare different independent channel reports of different constructions (number of connectors, length of cords, horizontal cables, etc). Used as the sole means of evaluating a vendor, independent test results may not provide a clear indication of repeatable system performance. Indoor/Outdoor Cabling
