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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?"
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.
An Education is the Font of All Liberty
We have TDR equipment and appropriate tools, but we still buy patch cables in bulk. We tested an assortment of ones we had made with cheap crimping tools, and they were all horrible. We can make decent ones, but it takes longer and costs more than buying them pre-tested.
Monster cables, dude, Monster cables...
~men are from earth. women are from earth. deal with it.~
I've learned the hard way when setting up a couple of clusters: You MUST use custom-made, cut to length cables to prevent a huge rats nets in the server room. Buying precut cables is a disaster. I had to rip out and completely rewire one cluster because I made that mistake.
However, you need to TEST the cables. And not just by plugging in and making sure it works, but a full ethernet validation tester.
I've been very happy with the Fluke Cable-IQ qualification tester, which doesn't just make sure that the wiring is correct, but actually tests the cable up to gigabit speed to make sure everything is kosher.
Test your net with Netalyzr
You can certainly screw it up if you do it yourself, for example you could forget the signal directional markings and then the signal would not know which way to go. Why do you think there are Ethernet cables at $500/1.5m? You think respectable companies are just trying to steal your money?
Violence is the last refuge of the incompetent. Polar Scope Align for iOS
I think you have a pointy haired boss who can't do anything himself. Thats why he has other people do the IT. I've run into these types of people before. He's probably the kind of guy that staples the crap out of cat cable and wonders why his network is down.
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?
We had a contractor come in and rewire our facility. They ran raw CAT 6 and hand terminated it, then TDR'd each run.
Your boss is unclear on the tools needed and the difficulty...just simple hand crimpers were all they needed. There's going to be
an impedance bump at the RJ anyway...the cable's not twisted there.
As to making them yourself or buying patch cables? It's way cheaper to buy them (I like L-Com) but if you need one *right now*,
(or a custom length) it's cheap to have a crimp tool, some RJs and a roll of cable handy in the corner of the office.
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.
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
Ask him how the premise wiring in every commercial building in the world is installed. They order patch cables from some commercial patch cable vendor for every run, riiiiiiiight.
Also, CAT5e is fine for what you are doing. I agree with the previous poster that you could practically use tin cans and a string for this.
These special dies, jacks, and connectors are called "CAT5" parts and you can buy them at Home Depot I think. Does that make them "special" ?
Yes, you can use handmade cables that are as good as mass-produced factory cables. But that really isn't the issue.
It's just not worth the time spent to cut and crimp your own lines anymore. In my experience, it was a more common practice years ago in IT. That may have had something to do with the fact that there weren't nearly as many PC's or ethernet ports in buildings as there are today.
My advice: Find a good supplier (i.e. not one that charges $800 for a 6 ft. adamantium-coated cable) and do something else with the rest of your time.
Bull! Entirely aside from what the submitter should do to protect their job, it is topical on slashdot to question whether DIY ethernet cables are any good, just as people on a home repair DIY site might discuss whether doing drywall yourself is worthwhile.
When the only answer slashdotters can imagine is "just pay somebody else to do it," that is the day there is no point reading here.
When the only answer slashdotters can imagine is "just pay somebody else to do it," that is the day there is no point reading here.
Hey, that was pretty good. What would you charge to make my posts for me?
Seconded. I make all my own patch ca$lw7 and3@0 datt trd!@m34ssion ha*F aslwts bben3n vereryu reliabl3233e.
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.
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
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
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.
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