Category Cabling: TIA-568a or TIA-568b?

Dealers on Remote Central debate Cat 5/6 wiring standards. Should you use TIA-568a or TIA-568b for residential installations?


Should you use TIA-568a or TIA-568b standards for Cat 5/6 residential installations? If you’re wondering the same thing, check out the dynamic discussion in the Custom Installers’ Lounge at Remote Central.

Dealers are debating which wiring scheme makes sense, and if it even matters. The responses are mixed, but pretty much even between A and B. Naturally, all dealers agree that on retrofits, make sure to check how the existing Cat 5/6 wires are terminated.

Here are some of the comments. Click here to read the entire discussion.

(Comments edited for grammar and clarity.)
We have always used 568a but have recently converted to 568b mostly because of the baluns that require that standard. Bottom line is it really doesn’t matter which one you go with as long as you choose one.
With POTS [plain old telephone service] becoming a thing of the past in residential and 568b being a lot more common, I’d say going with B perhaps is a better choice.
I use B all the time, but recently installed some phone lines in a doctor’s office where he uses a Panasonic non-KSU system using all four pairs, and after the third jack I realized I was using A.

Murphy’s Law actually came to the rescue this time, because when I went to punch down on the phone module, it turned out that the RJ-45 jacks are wired for A. Imagine that!

Then there’s the IT guy I spoke with recently who was a bit puzzled when I told him I use B. He was dissatisfied with that answer until I told him that when there’s an existing system, I look to see what they used, and use that.
My cousin runs the IT dept. at a hospital …. He uses B and said A is for phone guys!

As long as you’re consistent, either should work just fine.
If the house has an even number it’s A; if it’s an odd number then we go with B.
We do A at every job. Patch panel and wall plate are always A. Breakout cables/patch cables can be whatever we/you want.
I always use A. Only a handful of times have I seen B used and that was commercial.
I switched to B several years ago as A is really an old standard that was for the phone guys. B is used in all proper IT installations and if you’ve ever checked the pre-built patch cords you will notice that they are wired as per the B standard. Therefore, why make life difficult for yourself?
I got tired of the debate and created my own pattern: brown, blue/white, green/white, blue, orange/white, green, orange, brown/white.
Me too, 568C.
I guess all the people posting using B in a residential job never use the structured wiring cans. OnQ, Open House, Leviton, etc… ALL!!! use A. I have never seen it otherwise.

I agree it’s a pain in the butt to always have to look if the system you’re using is wired A or B. But until these manufactures get their crap together and pick one wiring scheme, we are going to have this confusion.
I use pro RJ-45 patch panels in larger homes and they are usually “helpfully” (confusingly) identified with both standards. It’s always bugged me that the shade of colors used on the punch down blocks on the patch panels and often on the keystones is sometimes so poor that orange can look like brown and green like blue. Yeah, I know, get a better flashlight ….
Actually, I would think that using A or B could make a huge difference in some products depending on the twisted pair that is twisted the most.

We have switched to B but always check to see what each product requests. I know that I tried to use a balun with A once and could not get it to work. The product did not mention anywhere that I needed to use B but once I made it B, it worked.

Just for kicks I tried again and tested everything. Didn’t work. As far as OnQ, I am pretty sure we used B on the last few jobs we did and had no issue. Sometimes it just does not matter. Sometimes it does.

About the Author

Julie Jacobson
Julie Jacobson:

Julie Jacobson is founding editor of CE Pro, the leading media brand for the home-technology channel. She has covered the smart-home industry since 1994, long before there was much of an Internet, let alone an Internet of things. Currently she studies, speaks, writes and rabble-rouses in the areas of home automation, security, networked A/V, wellness-related technology, biophilic design, and the business of home technology. Julie majored in Economics at the University of Michigan, spent a year abroad at Cambridge University, and earned an MBA from the University of Texas at Austin. She is a recipient of the annual CTA TechHome Leadership Award, and a CEDIA Fellows honoree. A washed-up Ultimate Frisbee player, Julie currently resides in San Antonio, Texas and sometimes St. Paul, Minn. Follow on Twitter: @juliejacobson