An Inadvertent Crash Course in PoE: The Top 4 Things You Need to Know

training roomAs I sat down to write this month’s post about Power over Ethernet, my mind immediately flashed back to my Berk-Tek job interview. Since it was a marketing position, my manager wisely constructed the interview process to include the creation of a mock marketing plan, and – gulp – a marketing presentation. Gotta prove you can do the job, right?

A week before my scheduled interview, he sent me a five-page document that contained an overview of our industry, some company background, product information on our LANmark-XTP cable, and – another gulp – an objective: Convince your audience that LANmark-XTP is the absolute best choice for High PoE applications.


My first order of business: Figure out what the heck PoE was.

My second order of business: Panic! I had absolutely no idea what PoE was. Or IP traffic. Or attenuation. Or cross-talk. Or Category 6A, for that matter.

I was a network cabling newbie. I came from the printing world, where we talked about inks and page counts, and maybe even the occasional embossing technique. All of these new “techie terms” were completely foreign concepts to me. I had a lot of work to do.

So I did the work. I learned a lot. I got the job.

I’ve learned even more in the two years since. The What-I-Don’t-Know bucket is still so much deeper than the What-I-Know bucket, but if I had to list the Top 4 Things to Know About PoE, they would be:

  1. There’s more power coming. PoE has been evolving since IEEE 802.3af came onto the scene in 2003. The latest standard in development – 802.3bt – is expected to be completed in 2018 and will allow for the transmission of up to 100W (Type IV). This would allow you to power large TVs, digital signage, advanced nurse call stations, and dozens of other devices. This new technology will be game changing for IP convergence, allowing us to connect and power devices and technology not even thought about yet.
  2. Heat is no friend to your IP traffic. The more you turn up the power, the more you turn up the heat. And the more heat, the more negative impact there can be on your IP traffic. Heat weakens signal strength and makes IP traffic more prone to errors and/or slow transmissions. It’s critical to install a cabling infrastructure that can effectively manage this heat rise.
  3. The proof is in the testing. Berk-Tek’s Cat 6A LANmark-XTP is the absolute best performing solution for High Power PoE.  Its discontinuous foil shield is specially designed to provide not only outstanding electrical performance without grounding, but also outstanding PoE performance. In a bundle of 240 cables (10 fully populated 24-port patch panels), with 100W of power energizing every pair in the bundle, LANmark-XTP had a temperature rise of only 19˚C (66˚F) in the center-most cable. In comparison, Category 5e products had a temperature rise of 37˚C (99˚F).
  4. LP is a guideline, not a requirement. LP (Limited Power) is an optional designation that was developed by UL in response to concerns about excessive heat rise when power levels go above 60W. The optional LP designation indicates that a cable has been evaluated by UL to carry the marked current in any reasonable worst-case installation without exceeding the temperature rating of the cable. But it’s important to remember that the LP testing performed by UL is performed under very specific installation constraints which do not represent real-world installation condition. So is it really the best way to ensure a safe and effective system operation?

Find the answer to this question and so much more information about PoE and LP on the Berk-Tek website.

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