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Handmade vs. Commercially Produced Ethernet Cables

An anonymous reader writes "We have a T1 line coming into our satellite office and we rely fairly heavily on it to transfer large amounts of data over a VPN to the head office across the country. Recently, we decided to upgrade to a 20 Mbit line. Being the lone IT guy here, it fell on me to run cable from the ISP's box to our server room so I went out and bought a spool of Cat6. I mentioned the purchase and the plan to run the cable myself to my boss in head office and in an emailed response he stated that it's next to impossible to create quality cable (ie: cable that will pass a Time Domain Reflectometer test) by hand without expensive dies, special Ethernet jacks and special cable. He even went so far as to say that handmade cable couldn't compare to even the cheapest Belkin cables. I've never once ran into a problem with handmade patch cables. Do you create your own cable or do you bite the bullet and buy it from some place?"

23 of 837 comments (clear)

  1. How much is your time worth by linzeal · · Score: 5, Insightful

    While it may be cost effective to crimp and cut your own cable when you are making less than 20 dollars an hour once you are making 20 dollar+ just buy it.

    1. Re:How much is your time worth by Z00L00K · · Score: 4, Insightful

      It depends on the situation and the reason for the cable.

      Sometimes there are restrictions for routing the cable that makes a prefabricated cable unusable.

      And you may sometimes run into problems with a handmade cable, but often it does work just fine. If you get problems - just remake one contact at a time. If you have a decently modern intelligent switch you can also monitor the port for data errors, and if you don't have any errors it's good enough.

      As for cabling quality - all the outlets in buildings are usually contacted by the cable jocks from the installation company and they do a simple test and then moves on to the next. I doubt that the quality from a hand made cable and those outlets are much different.

      --
      If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
    2. Re:How much is your time worth by zappepcs · · Score: 4, Insightful

      time out! How does making one cable run constitute reason for determining ROI on making cables based on cables per hour etc?

      There are some of us who can whip out a standard 15ft Cat5 cable in about twice the time it takes to unwrap a commercially purchased cable. If you need custom sized cables, it's far easier and cheaper except for very small number of situations. If you have one cable run to do and the parts available, it makes no sense to go buy one. It's not like you're going to run out and get a 39 meter Cat6 cable at lunch time in the Mall.

      Now, if you need 50 of them? perhaps a different story, but same story goes when you need 5000 of them. Savings get bigger with bulk. In this case, it was for a single cable. My suspicion is that his boss has never actually seen a well made cable created in front of his eyes. Remember grasshopper, all great Samurai swords were made by hand, not a machine with expensive dies.

      Whatever happened to quality custom workmanship? It's almost as if people expect that it can't be done anymore? WTF?

    3. Re:How much is your time worth by camperdave · · Score: 5, Insightful

      Set up a dummy company, and get them to sell you the $300 cables for $250. Then crimp the cables and sell them to yourself. You pocket $250 less materials, the boss gets his "professionally made" cables, and everybody is happy.

      --
      When our name is on the back of your car, we're behind you all the way!
    4. Re:How much is your time worth by postbigbang · · Score: 4, Insightful

      Uh, what part of unshielded twisted pair don't you understand? The whole idea of the twists assuages any reasonable amount of both reception and transmission externally. Modern endpoint tranceivers are really good at signal to noise problems; you can usually make cables quite a bit longer than the IEEE specs call for with total impunity. And Cat6 isn't necessary, either, just quality Cat5/5e is fine.

      The only place where fast transmission cables have problem with Ethernet is at the connectors. Crosstalk there, and ONLY THERE, can be a problem unless you do something pretty unnatural to the cable. RJ-45s simpily suck because of the parallel tines. Crimp according to directions. Takes about 30sec a side. If you're worried, shoot a TDR down the line. Fluke and others make some pretty cheapo testers, or bug a cable guy to test it for you. This is not rocket science. Don't wimp out and have someone else do it. Buy quality connectors and cable, and just do it. Get the color code, follow it, and move on.

      --
      ---- Teach Peace. It's Cheaper Than War.
    5. Re:How much is your time worth by thsths · · Score: 4, Insightful

      >Welcome to the real world, where standing waves on transmission lines do exist, and you can choose lengths carefully based on the frequency going down it.

      That may be true for RF, but the whole point of communication is that you get more than a single frequency - a frequency spectrum. So matching your cable length is no good for Ethernet.

      In practice, there are hardly issues with standing waves, because the cable is unidirectional. So two reflections have to occur, and there is additional damping in the cable. So unless your impedance is way off, you should be fine. Even a 10% mismatch is perfectly harmless.

    6. Re:How much is your time worth by Jeff+DeMaagd · · Score: 5, Insightful

      The real acid test would be to get one of these TDR units, buy 10 cables from each of two or three reputable companies and compare it to the results from 10 cables done in-house.

      All this talk without an objective stress test is pretty pointless.

    7. Re:How much is your time worth by shogun · · Score: 4, Insightful

      But are they exactly the right length to pull from A to B, or do you have some coiled up uglies?

      A forward thinking IT professional knows to leave some slack in the cables, otherwise plate tectonics makes fools of us all.

    8. Re:How much is your time worth by jemenake · · Score: 5, Insightful

      And here's another tip when making several cables at once...

      Make one long cable of the total length of all of the cables you want, and terminate the two ends and test the cable. Then, you know those two ends are good. Then, for your first "finished" cable, snip off the length you want, and terminate the snipped end. Then, test the cable. If it fails, you know which end needs fixing.

      Then, with the remaining slightly-less-long cable, terminate the snipped end of that, and test. Then, snip off the next length you need, etc...

      I used to just pull off the length I needed from a spool, crimp the two ends, and test. But, if the cable failed the test, and I couldn't see where the problem was, I'd have to flip a coin to decide which end to re-do first. The above method avoids the coin flip. You'll know which end you have to re-do.

  2. If the Belkin cable fails, you can blame Belkin by Glass+Goldfish · · Score: 5, Insightful

    Why put your neck on the line? If you make a cable and anything goes wrong, even if it happens later on, you're blamed. If something happens with the Belkin cable, you can blame Belkin. Even if it isn't Belkin's fault. Especially after your boss has told you to do something. Whenever you go up against an authority figure, the best you can hope for is proving them wrong. It's better to say "What a great idea boss!" and buy the cable. If it works, great. If it doesn't work, don't rub it in. Besides, do you really want to crimp your own cables?

    1. Re:If the Belkin cable fails, you can blame Belkin by Just+Some+Guy · · Score: 4, Insightful

      If something happens with the Belkin cable, you can blame Belkin.

      That presumes:

      1. You make crappy cables.
      2. Your boss is watching over your shoulder to see whether it's a homemade or bought cable.
      3. All of your bought cables are labeled by the manufacturer.
      4. Your boss cares beyond "is it fixed yet?"

      Besides, do you really want to crimp your own cables?

      Yeah, but I'm one of those crazy people who fix their own fences, hang their own ceiling fans, build treehouses for their kids, and generally like to do things not conducive to the strictly consumer lifestyle.

      --
      Dewey, what part of this looks like authorities should be involved?
  3. Doubt he's correct, but believe him anyway! by zaf · · Score: 4, Insightful

    Wait a minute. Your boss is telling you to buy cables instead of toiling to make your own, and you're _complaining_? I don't think a self-terminated link of CAT6 will have the slightest trouble maintaining 20 megabits, but that's not the point.

    Word of advice, take his word for him and nod. If he's willing to spend money to make your job easier, then keep that job!

  4. Not worth the responsibility by hhaarrvv · · Score: 5, Insightful

    Your cables would be fine, but if ANYTHING ever goes wrong the first thing your boss will say is "It's probably that damn cable you made when I told you to buy one." It's just not worth it.

  5. Re:your boss sucks at making ethernet cables by causality · · Score: 5, Insightful

    Obviously your boss isn't good at making cables. While if you lack the skill to do something like make cables with care you're going to have problems, there's no reason that you can't make your own cables and have them perform just as well as the ones made by a machine in a factory.

    They can put it under the "Tech" section if they like, but this is really another disappointing Ask Slashdot. It's disappointing because too many of these have this format: "my boss at work wants me to do X, but I'd really rather do Y; what are the merits of X versus Y?" All of them need to be summarily rejected, with a polite e-mail sent to the submitter which says "within the bounds of the law, you need to do what your boss asks you to do whether or not you necessarily agree with it. If you cannot convince your boss to do otherwise, and this is a problem for you, perhaps you should consider working elsewhere."

    The other disappointing category of Ask Slashdot-type submissions are those questions that are factual in nature and have only one correct (and rather well-known, easily researched) answer. Asking a large group with varying levels of expertise makes a lot of sense when there are multiple possible solutions to a problem and there is room to be creative. It makes no sense when it's more of a yes/no question -- remember the recent Ask Slashdot that asked whether spam is increased by trying to opt-out of spam e-mails? That's an excellent case in point, and not atypical either. That should have been an "Ask Google", not an "Ask Slashdot".

    I think it's a shame that the quality of these particular submissions are on the decline. There's nothing inherently wrong with the "Ask Slashdot" format and there are a lot of very knowledgable people who browse this site. I'd love to see how creative they can be. It's just never going to be as good as it easily could be when it's handled this way.

    --
    It is a miracle that curiosity survives formal education. - Einstein
  6. Re:your boss sucks at making ethernet cables by timeOday · · Score: 5, Insightful

    All of them need to be summarily rejected, with a polite e-mail sent to the submitter which says "within the bounds of the law, you need to do what your boss asks you to do whether or not you necessarily agree with it. If you cannot convince your boss to do otherwise, and this is a problem for you, perhaps you should consider working elsewhere."

    Bull! Entirely aside from what the submitter should do to protect their job, it is topical on slashdot to question whether DIY ethernet cables are any good, just as people on a home repair DIY site might discuss whether doing drywall yourself is worthwhile.

    When the only answer slashdotters can imagine is "just pay somebody else to do it," that is the day there is no point reading here.

  7. Re:your boss sucks at making ethernet cables by Phasma+Felis · · Score: 5, Insightful

    They can put it under the "Tech" section if they like, but this is really another disappointing Ask Slashdot. It's disappointing because too many of these have this format: "my boss at work wants me to do X, but I'd really rather do Y; what are the merits of X versus Y?" All of them need to be summarily rejected, with a polite e-mail sent to the submitter which says "within the bounds of the law, you need to do what your boss asks you to do whether or not you necessarily agree with it. If you cannot convince your boss to do otherwise, and this is a problem for you, perhaps you should consider working elsewhere."

    I don't know about you, but I was hired for my technical expertise. It is part of my job description to let management know when they are making bad technical decisions. If they still insist after that, then sure, I gotta shrug my shoulders and do it; but until then, it's my job to find out the facts and make sure they stay informed...which is exactly what the questioner is doing.

    Save the "shut up and do as you're told" bit for McDonald's burger-flippers. We're professionals here.

  8. Drill test by salesgeek · · Score: 5, Insightful

    Best advice I've ever heard on cabling:

    If you have to drill holes to run it, make your own. If you don't buy it premade.

    Second best advice:

    Test it all. Even if it comes in a shrink wrap package.

    --
    -- $G
  9. Bad Attitude by PinkyDead · · Score: 4, Insightful

    This principle of going with the provider you can sue over the one you can rely on is becoming far too prevalent.

    I'm not saying that there's anything wrong with Belkin, and I think in this situation the pre-made cables are the better option.

    However, in a more general sense, I'd prefer that my systems didn't go down rather than being able to point the finger when they do. If you are the front end provider of a service your customers are not going to be placated by the fact that, even though all their data is gone, you are currently seeking glorious retribution from the guy that solders the LEDs onto your motherboards (or whatever).

    On top of this, when things go tits up at three o'clock in the morning - you can be sure the Belkin shop won't be open.

    --
    Genesis 1:32 And God typed :wq!
  10. Re:Just do what your boss wants by Ephemeriis · · Score: 4, Insightful

    It's clearly not your company's core business to make their own patch cables. It may be fun for you to wittle down your own toothpics from lincoln logs but if it's not in your job description it ain't going to fly. Seriously, just buy the damn stuff and do what your boss has asked.

    Exactly.

    We buy all our patch cables in bulk. There's no reason for me to assemble a new cable every time we want to patch in another machine. It may not take long to throw together a 6' cable, but why waste any time at all? Break open a package and plug it in. Done.

    We do keep a couple spools on hand, and some wiring tools. If we absolutely need a 15' cable and we don't have any on hand we'll throw one together...

    Or if we really need a new wall jack somewhere... It's good to have the capability to do some of your own wiring if necessary... But for anything substantial we'll contract someone else to do that, too.

    But, really, that isn't what I'm paid to do.

    --
    "Work is the curse of the drinking classes." -Oscar Wilde
  11. This is not a time/money issue by exploder · · Score: 5, Insightful

    This is a CYA issue. Your boss does not want to explain to HIS boss, when a cable goes bad and the company is losing $large_number per hour until it is diagnosed and fixed, that he authorized one of his tech guys to use "homemade" cables.

    --
    Yo dawg, I heard you like the Ackermann function, so OH GOD OH GOD OH GOD
    1. Re:This is not a time/money issue by exploder · · Score: 4, Insightful

      Doesn't help when the first question is, "who supplied that cable"? I don't know if you've been in a "root cause" meeting, but they DO get all Sherlock Holmes on that shit, I assure you.

      --
      Yo dawg, I heard you like the Ackermann function, so OH GOD OH GOD OH GOD
  12. Not as such... by Anonymous Coward · · Score: 5, Insightful

    They are made at specific lengths for marketing reasons. All of the "transmission line" characteristics of Ethernet cable have been solved for every length within the specified maximum.

    I have a whole data center (~32 rows of 22 racks) fully cabled with lengths ranging from 100 meters to 5 inches (crossover between 1U boxes). They are cut to custom lengths, source to destination. Where their port is on the router and where they were placed in the tray add and subtract inches here and there. They run to the patchpanels in bundles about 7 inches in diameter. We have no problems with crosstalk, reflections, intermod and what have you.

    If this were coaxial Ethernet we could have a fun discussion... but those days are well behind us.

  13. Re:your boss sucks at making ethernet cables by kimvette · · Score: 5, Insightful

    Here's how people screw up cables:

    1. They just match colors at either end and don't pick a standard pinout (T568A or B). That might result in a usable 10mbps link, but it won't work at 100 or 1000.

    2. They mix 568A and 568B - usually wiring A in the wall, and using premade B patch cables. Instant crosstalk. OK on very short runs, but anything longer than 80' to 100' will become problematic with many NICs.

    3. They score the insulation. Use the right tools, and adjust the tension on the stripper.

    4. They only strip 1/2" of insulation and try to organize the cables and jam it in, so you don't get a clean connection on all the conductors - or might miss one completely. Strip the insulation back 2", then you have room to sort the conductors, trim them neatly then you can slide them all the way to the end of the terminator, then the clips will "bite" each conductor twice - cleanly, resulting in a good connection and a strong link.

    Your boss sounds like an idiot and a hack.

    If you're going from the wall to the PC I'd say yeah, buy a premade cable and save on labor. Just buy a good one. Believe it or not monoprice's cheap stuff is extremely good.

    From the patch panel to the switch, it depends on the length. Will a premade cable fit the length well? Go premade. If not, then make the cables.

    Ultimately though, your boss is the boss. If he insists on hanging patch cables loose through the wall, etc. just document it in email, send it to him with your recommendation, etc. so that when he comes back to you complaining that it looks hack or that the cabling was overpriced, you can remind him that you recommended otherwise.

    --
    The Christian Right is Neither (Christian nor right). See: Matthew 23, Matthew 25, Ezekiel 16:48-50