atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Input on pricing for multi-jack location

Does anybody use 568B on a regular basis? I don't understand why you would - why not keep the blue and orange pairs the same order as a voice jack?

I agree that patch panel for phone jacks are a waste of time and money. I've seen it done in a few locations (80+ jacks) and it can easily turn into a rat's nest with unneeded points of failure. However I do like the idea of having a tie between your data cable rack and your telephone punch blocks so you can convert a cable from voice to data and vice versa just by adding jumpers and patch cords.

I use 568b on a regular basis only because it seems to be the growing standard for commercial use. I know that with structured wiring 568a is primarily used. just making it easy on the guy following me I guess.

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NextWave Communication Technologies

Have only used 568A once in 15 years. Never been to a site where 568A was used. Majority of the phone systems only use 1 pair anyways, the few systems that I install that aren't (Partner) is wired for an RJ45 so a straight thru patch cord will work regardless if its 568A or 568B. If you are punching the cable down on 66 or 110, is it really that hard to punch down a X-cut on blue and green rather than orange?

Up in the great white north here, the "B" standard is a pretty rare bird. It's always a royal pain when we run into it. I still don't get why it was created in the first place.

I find the older installs I come across to use 568A while newer installs almost always use 568B.

I also agree with Coral about the patch panels. What a pain!!!!

BY far 568b is used over 568a in my area, even though i like 568a more for standardization reasons. does any one know why or how att chose this scheme over 568a??

if you use 568b, any single pair mounting cord/device will be connected to white/blue pair (the two center pins) 568a makes the two center pins on the voice station connecting block into the white/green pair. In most voice systems, documentation says connect the basic two wire station to white/blue. also note that rj11-rj12 starts with the first pair being the two center jack pins i.e. blue/white or red/green

Dude, the center pins or pins 4 & 5 on a 568A or 568B are always the blue pair.

you are absolutely correct. I take it all back

To anyone interested in historical information, the current 568B standard was originally referred to as "AT&T 258A". It was kind of stupid because that was simply referring to the ever-popular adapter made by Western Electric/AT&T/Lucent/Avaya/Whatever to convert an existing 1A2 (25 pair) station cable to six four-pair modular jacks.

A four-pair modular jack IS NOT an RJ45, but that's another issue entirely. I will bore you with that subject later.

Anyway, early electronic telephone sets made by Western Electric for AT&T and the Bell companies used their special 4-pair jack. They intentionally configured the pinouts differently since it was way too easy to plug a 2-pair plug into a 4-pair jack. Their electronic phones (Dimension METS, Horizon METS, etc.) required separate pairs for power and data, they arranged the jack so that pairs would be in "protected" positions. This would avoid accidental contact through a 2-pair cord insertion and the potential for a blown fuse. Hence, the AT&T 258A standard was born. They seemed to have developed this standard to protect themselves from avoidable service calls.

I am pretty sure, but not positive that data rode on pins 1/2 (W-Or) and power was on pins 7/8 (W-Bn). If I am correct, this left pins 3,4,5 & 6 out of harm's way for the accidental connection of consumer level phones, especially Trimline phones with dial light bulbs connected to pins 3 and 6 (AKA black and yellow). We old timers may also remember "A leads" present on pins 3/6. I really think that they left these pins vacant in their standard to avoid short circuits from A leads, but who really knows?

AT&T developed this standard LONG before EIA/TIA standards "adored" today even wore diapers. This standard might not be "USOC" compatible from an end-user standpoint, but seriously, are any of us on this site concerned about orange or green? I mean, 568A or B is kind of insignificant as long as the jack/patch panel is wired using the same standard.

Where my company is located, there's a huge Bell/Avaya presence because of the huge Federal Government market, so AT&T's 1974 era wiring standard is the norm. Makes perfect sense to me!