It’s likely Cat6 cables are the last thing you think about until you spend a lot more than you think you should on new LAN infrastructure. The handsome sum of a new 10-gigabit network switch has you looking for ways to save on budget. Maybe you’re thinking about reusing old cabling to cut costs.

That could end one of two ways. You can save cash and get great throughput anyway; or you can sabotage your new expensive LAN with bad network Ethernet cables.

Here’s the hard truth about Cat6 cables. According to Fluke Networks, around 80% of the so-called category 6 compliant cords on the market today fail to meet the specific telecommunications requirements under ANSI/TIA-568-C.2 and ISO/IEC 11801:2002.

Even with new Cat6 cables in place, you may not necessarily get the performance you paid for.

When is Category 6 not Category 6?

Because cable certification happens on the honor system, there are many opportunities for fraud. Unless you have access to a digital copper Ethernet cable tester, you’ll never know if you are getting the maximum throughput possible. For too many shady manufacturers, the only difference between Cat 5e vs Cat 6 cable is what they print on the cable jacket and packaging.

How can you avoid getting ripped off?

First, make sure your wiring contractor puts transmission specifications in writing. Insist on certification of each run—even if it costs extra. If you want, you can even specify the specific brand and model of Ethernet network cable to be run and purchase it yourself.

When purchasing patch cables, the issue is no different. Price is not always an indicator of quality. Keep in mind that the phrase “100% tested” may well mean no more than a continuity test by the manufacturer.

A large enough organization might want to consider purchasing its own 10gig Cat6 cable analyzer. (They start around $13,000). If that’s out of your budget, check with local cabling contractors to see if they will test a few patch cable brands for you so you can have greater confidence in your Cat6 purchases.

Are your Cat6 cables in good shape?

Even if all your Cat6 cables met specs at the time of purchase, performance may suffer after several years of use. Something as simple as a hard bend in a cable can halve its throughput.

If you reuse older cables, how sure are you that your core and access layer patch cables are still delivering their designed bandwidth?

Start with proper handling of copper Ethernet patch cables.

• Never bend an Ethernet cable with a radius less than one inch—the diameter of a quarter. A sharp bend or a kink will reduce the throughput of the cable.
• Never run patch cords along the floor where they can be stepped on. Crushing the cable underfoot can pinch or twist the cable pairs, increasing cross talk and reducing throughput.
• Do not hang things from a patch cord. Ethernet cable is not a structural item. Weight will stretch the cable (increasing cross-talk), adds pressure on any kinks in the cable, and even pulls on the RJ45 connectors. Remember the quarter rule about bending cables.
• If a cord looks worn, or a RJ45 connector won’t seem to latch into place, replace it.

Think about this: you just spent almost $5,000 on a new Cisco access switch and yet you reused the same cables that have been in place for several years. It usually costs at most $250 to replace all the access patch cables. Why take a chance on failure when new cables are only 5% of the switch value?

Or imagine you just spent $20K on a new database server. Even with multi-port NICs, one bad cable torpedoes the performance on your investment.

Do think your network is running slower than it should? Check the cabling before you start buying hardware; you might stand to save a huge chunk of budget.

Three cable rules of thumb

1. If you are replacing the hardware after several years of operation, consider replacing the cables too.
2. If a cable looks crimped or tweaked inside the jacket, throw it out so it cannot be reused.
3. Avoid tight radius bends and using patch cables to support other Ethernet or power cables.

Don’t let a $5 cable ruin your IT investment; have contractors verify throughput for Cat6 cables or test yourself .
  

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