Cabling – From Category 5 to Category 6, the Big “E’s” and the Little “e’s” Demystified

There are certain absolute standards related to network cable.  These are; Category 5e, Category 6 and now Category 6a.  These are the copper data cable choices that are recognized as standards in the industry. Category 5 is no longer produced as part of the standard, being replaced by Category 5e.

There are other terms, however, that are often thrown around, like Cat 5E (“big E) and Cat 6e (little and big e).  These are not part of the industry standards, these are marketing tools/designations used by some cable manufacturers.  The reason is simply that their cable performed better in their lab tests than the industry standard thresholds, so they slapped an “e” on it, or sometimes a bigger “E”.

Category 5 came out in the early 90’s and was a huge advantage to faster networks (let’s not mention Category 4).  Category 5 was rated for 100 MHz.  The cable had 8 individually insulated, 24 gauge conductors separated into four twisted pairs. The Category 5 standard was pushed so fast by the industry to support IEEE protocol that it did not address numerous crosstalk issues.  These issues created errors in the transmission of data down the cable.  This was corrected by the Category 5e standard.  Category 5e is rated for 100 MHz as well, but it does have different twist rates on the pairs of cables to address the crosstalk issues.

Then along came Category 6.  Slightly heavier gauge conductors, and usually with a separator membrane between the pairs, Category 6 is rated for 250 MHz.  The newest/latest standard is Category 6a, or “Augmented Category 6”.  Each pair has a dividing membrane in addition to the main pair separator membrane.  In our experience with Category 6a, the overall cable jacket seems much thicker and heavier than its Category 6 counterpart.  Category 6a is rated for 500 MHz, doubling that of standard Cat 6.

For 10/100/1000 BASE-T ratings the length limits on all are 300’ (not including length for patch cables at each end).  For 10 Gig applications, Category 6 is rated only to about 180’.  Cat 6a, however, does not have this limitation and can run 10 Gig the full 300’.

So when considering a “big E” solution over the standard, it is important to weigh the cost differences with what you are actually getting.  A cable in the lab can certainly perform at better levels, but there is no guarantee that the performance will match the lab once installed.  Does a patch cable or a jack match the same specifications as that “enhanced” cable?  A cable system is only as good as its weakest link, so using the same quality throughout is important.  Another consideration is that cabling testers will only test to the standards, so there is no real way to gauge better performance.  A quality installation is usually the key to maximizing the performance of your cabling materials.  Limiting the number of mistakes; like kinked cables, over-stressed pulling, limited or no untwisting of pairs for termination, during install will provide you with the best results.

(Article by Charles Bressler – ECS Account Manager)

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