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Thread: Cat 6 termination, A or B?

  1. #21
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    Quote Originally Posted by hbiss View Post
    Ahhh! Now there's a breath of fresh air!
    -Hal
    You forget I was a regular at the Sundance forum for some years (as you were)... and I figured I would correct 'em before you got ahold of them.
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  2. #22
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    Quote Originally Posted by infinity View Post
    That's what we thought too, until the cameras didn't work. When we tried one of the cable supplied with the cameras it worked. When we changed the pinning to reflect what the manufacturer specified because of the individual pair twists it worked.
    is possible to have a wiring error and not use designated conductors of a pair, but you need to make same mistake on both ends of the cable for it to pass testing, then you still have proper continuity from one end to the other, just that not all "pairs" will be individually twisted like intended and it can reduce performance levels.

  3. #23
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    Quote Originally Posted by infinity View Post
    That's what we thought too, until the cameras didn't work. When we tried one of the cable supplied with the cameras it worked. When we changed the pinning to reflect what the manufacturer specified because of the individual pair twists it worked.
    There is no standard for pair twist rates of different colors. One mfg might have the blue pair barely twisted (lowest rate), others might have it the tightest. It's likely you had a bad termination the first time and a good one the second.

    I'd be willing to bet I could take a piece of cat 6 cable and wire it following 568B standard tho screwing up the colors and as long as both ends are identical, it would certify. Identical meaning brown on 1 and 2, blue on 3 and 6, orange on 4 and 5, and green on 7 and 8 (instead of the correct orange, green, blue, brown, respectively). The pair twist rates are important only in that they differ from one another.

    One can take good cat5e cable that was installed to EIA/TIA spec (supported every 5', not kinked, not overpulled, under 100M in length) and put it down on cat6 keystones and patch panels and get it to certify cat6. Neat little trick should you ever get a customer that wants an upgrade but doesnt want to recable the entire building. Now 6a, dunno if it would pass that (Ive only ever done the aforementioned trick 'on the bench', mind you).

    If you remember that camera mfg and stick by your story, please PM me the name - I never want to buy something that does not work to TIA/EIA specs.

    btw, anything that works on cat5(e) will work on 6, 6a, and even 7 - and those cables have progressively tighter twist rates.
    Electricians do it until it Hertz!

  4. #24
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    Quote Originally Posted by kwired View Post
    is possible to have a wiring error and not use designated conductors of a pair, but you need to make same mistake on both ends of the cable for it to pass testing, then you still have proper continuity from one end to the other, just that not all "pairs" will be individually twisted like intended and it can reduce performance levels.
    If you punched down the pairs on pins 12, 34, 56, and 78, you'd wind up with 2 split pairs instead of 1 - green should be on 3 and 6, blue on 5 and 4. Even if identical at both ends, you'd be using one wire of the green pair and one of the blue as pins 1236 are used for signal transmission - that could get very ugly. Such a punchdown would never pass even a cheapie tester tho.
    Electricians do it until it Hertz!

  5. #25
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    Quote Originally Posted by JFletcher View Post
    If you punched down the pairs on pins 12, 34, 56, and 78, you'd wind up with 2 split pairs instead of 1 - green should be on 3 and 6, blue on 5 and 4. Even if identical at both ends, you'd be using one wire of the green pair and one of the blue as pins 1236 are used for signal transmission - that could get very ugly. Such a punchdown would never pass even a cheapie tester tho.
    You may have data speed issues, but if you accidentally swapped say the orange and blue, but kept the corresponding white that goes with each in the designated position, a continuity only test would still pass if you swapped them on both ends.

  6. #26
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    Quote Originally Posted by hbiss View Post
    Ahhh! Now there's a breath of fresh air!



    Lets not get carried away now. The USOC designations are still used although many designations like RJ-45 have no use today.

    RJ-11 is your standard 1 pair phone jack or plug- 6p4c or 6p6c with T&R wired to the center pins 3&4.

    RJ-14 is a 2 pair 6p4c or 6p6c jack or plug with the first pair on 3&4 as above and the second pair on 2&5. It could be used for two lines or commonly for office phones that use two pairs.

    Extra credit: Does anybody know what a RJ31x jack is?

    -Hal
    Don't recall how it's wired off hand, but it's for line seizure by security or fire alarm equipment.

    ---------------

    Whoops! Answered before reading the rest of the posts. Day late and a dollar short.
    Last edited by gadfly56; 07-30-17 at 11:17 AM.

  7. #27
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    Quote Originally Posted by JFletcher View Post
    Neat little trick should you ever get a customer that wants an upgrade but doesnt want to recable the entire building.
    Probably true 99% of the time but if your customer actually has or intends to on day upgrade to equipment that is capable of taking advantage of data transfer rates above 1 gigabit then CAT6 jacks and patch panels on CAT5E, regardless of how well installed, will not be sufficient. I would just make sure the trick is not pulled without that understanding.

    1N73LL1G3NC3 15 7H3 4BILI7Y 70 4D4P7 70 CH4NG3.

  8. #28
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    Quote Originally Posted by JFletcher View Post
    I'd be willing to bet I could take a piece of cat 6 cable and wire it following 568B standard tho screwing up the colors and as long as both ends are identical, it would certify. Identical meaning brown on 1 and 2, blue on 3 and 6, orange on 4 and 5, and green on 7 and 8 (instead of the correct orange, green, blue, brown, respectively). The pair twist rates are important only in that they differ from one another.

    One can take good cat5e cable that was installed to EIA/TIA spec (supported every 5', not kinked, not overpulled, under 100M in length) and put it down on cat6 keystones and patch panels and get it to certify cat6. Neat little trick should you ever get a customer that wants an upgrade but doesnt want to recable the entire building. Now 6a, dunno if it would pass that (Ive only ever done the aforementioned trick 'on the bench', mind you).
    couple thoughts....

    i read that the turn differences of the pairs were
    a ratio to each other, not as absolutes on their own,
    so that a manufacturer, as long as those ratios were
    observed, could produce compliant cable.

    i've got two cable certifiers that, while neither of them
    is a $ five digit device, every cable i've ever tested with
    them, at cat 5 or greater, assuming it's wired correctly,
    has never failed a cat 5 cable or terminations at 1ghz cat 6.
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  9. #29
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    Quote Originally Posted by luckylerado View Post
    Probably true 99% of the time but if your customer actually has or intends to on day upgrade to equipment that is capable of taking advantage of data transfer rates above 1 gigabit then CAT6 jacks and patch panels on CAT5E, regardless of how well installed, will not be sufficient. I would just make sure the trick is not pulled without that understanding.
    Agreed. If the customer wants future proofing, we always recommend conduit vs cable-flavor-of-the-moment.

    Some of the best Cat5e cable comes very close to meeting cat6 spec:

    "CommScope Enhanced Category 5e (Cat5E) cables exceed ANSI/TIA-568-C.2 Enhanced Category 5 (Category 5e) and ISO/IEC 11801 Class D
    performance requirements by significant margins, providing extra headroom for a more robust cabling system.

    Re: top-level install, most cat5e cable I've seen installed is anything but top notch, a fair amount of it probably would fail a cat5e certification.... mostly due to poor terminations... max untwist at the jacks/patch panels is 0.5" - basically stitches right up to the IDC "teeth"
    Electricians do it until it Hertz!

  10. #30
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    Quote Originally Posted by Fulthrotl View Post
    couple thoughts....

    i read that the turn differences of the pairs were
    a ratio to each other, not as absolutes on their own,
    so that a manufacturer, as long as those ratios were
    observed, could produce compliant cable.

    i've got two cable certifiers that, while neither of them
    is a $ five digit device, every cable i've ever tested with
    them, at cat 5 or greater, assuming it's wired correctly,
    has never failed a cat 5 cable or terminations at 1ghz cat 6.
    Yeah I wanted a Fluke DTX 1800, glad I didnt plop down the 10k for it at the time, and another 10k for the fiber modules... I got out the commercial v/d/v just about the time we considered offering certification... most hotel owners dont even want to pay for conduit...

    I'd have to look up the turn ratios to see what they are in relation to one another, tho lets say they are the following:

    Blue pair: 1.08 turn per inch
    Green pair: 1.35 turns per inch
    Orange pair: 1.5 turns per inch
    Brown pair: 1.2 turns per inch

    The ratio of orange to green is 1.111..., ratio of green to brown 1.125, and brown to blue again 1.111.... Now, these arent measured specs, but they are close enough to see that the ratio of twist rate between pairs is roughly the same from one to another. Primary difference between cat6 and cat5e is cat6 is usually 23ga wire and 5e 24, and some cat6 has an internal spline divider.

    Cat5e at the time I was putting it in, most of the good stuff was rated 350MHz even tho the spec is 100MHz... cat6 spec is 250MHz, tho the cable is, I believe 550MHz, and while that's not the only diff between them (all cross talk specs are tighter, overall max speed is higher), I agree that well installed cat5e on premium components will far exceed its minimum specifications.
    Electricians do it until it Hertz!

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