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First of all, I must say I've never had a problems with making cables by myself, last years stopped using cable testers just because they always say the cable I've made is ok.

But I see there's a lot of the factory-made cables on the market, they became cheap and in addition you may choose any color for the better management. Some people say the factory made cable is always better than you may do.

As there could be couple of the different situations, let's split a question:

  • buy or make a cables for the networking inside a rack?

  • buy or make for the networking outside i.e. to users' computers, to other racks etc.?

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you meant BUY or MAKE right ? –  Prix Aug 14 '10 at 6:08
    
Is not it superuser.com question? –  Gennady Vanin Novosibirsk Aug 14 '10 at 14:55
    
@vgv8 I guess not. I don't care where users get their cables, when you need 10, you may build or buy, nobody cares :) –  disserman Aug 14 '10 at 15:47
    
@Prix, right, thanks for the correction –  disserman Aug 14 '10 at 16:17
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Does your tester cost more or less than $3000? If it just checks pinouts, it is nearly worthless –  chris Aug 15 '10 at 15:08
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15 Answers 15

up vote 27 down vote accepted

Personally I would always buy cables and always do buy cables in large volumes.

The reason for this is that unless you are making cables for home you are making cables for a business. It takes time to make cables and you are paying people/you are being paid by the organisation you are working for. Unless you are making them in very large quantities the amount you save from making cables yourself does not cover time cost of the time taken to make the cables.

Also as you said you can buy multiple colours and most lengths, failing that there are companies out there who will make you any length of cable you want cost effectively.

Hope this helps.

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I've got to go with this answer. It simply isn't cost effective for my employer for me to be spending time making cables - unless the cable is for a specialist task or length that can't be purchased easily. –  RobM Aug 14 '10 at 16:24
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In addition, it doesn't matter how accurate you are, you're statistically much more likely to make a faulty cable than the machine is. I don't want to wait until 3am to find out that I almost-but-not-entirely crimped a cable. –  Matt Simmons Aug 14 '10 at 16:25
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I understand this, but this can also be a good down-time activity. –  Joel Coel Aug 14 '10 at 23:14
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this should be noted that this would be for patch cables, its a bit crazy/against code to run prefab cables through walls –  Jimsmithkka Aug 23 '10 at 11:15
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I can not make cables at a rate fast enough to compete with the prices from MonoPrice or Ziotek.

The only exception I make is for cables that are particular long, that have to pulled through conduit or holes without connectors on them, or when exact size matters. In that case, I do my best to borrow a appropriate cable testing hardware to test my work.

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My preferred method is to keep a stock of premade cables on hand (in a couple standard lengths), but always have a spool of wire and a box of plugs as well so I can make longer or custom-sized cables on demand (or if I run out of the premade ones).

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It just doesn't make sense to me to make cables. You save some money on the materials, but you quickly surpass any savings with labor.

You also probably aren't going to test and certify every cable that you make, meaning that it could turn into a hidden little problem in the future. I'm a big supporter of having quality cabling. After all, if layer 1 is unstable, the entire stack falls apart.

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I haven't heard anybody refer to cabling as Layer 1 in a long time. Typically, cabling is referred to as Layer 0 (even though there is no Layer 0 in the OSI model). Layer 1 represents the physical specifications and signaling, but not necessarily the cabling itself. Ethernet is a Layer 1 specification, but can be run over multiple types of cabling. A T1 line is the same way. Cat5, Cat5e, Cat6, etc. are cable specifications/types, not signaling, pinouts, etc. Its one of those minor points that bugs me, like when somebody says "ATM Machine" or "NIC Card" :) –  peelman Aug 14 '10 at 4:55
    
@peelman - Fair enough. Stable cabling leads to stable signaling though. So I still think the phrase is valid. –  Jason Berg Aug 14 '10 at 18:06
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@peelman: Layer 1 is the Physical layer, and the cable is physical. Ethernet as the broad concept actually covers both Layer 1 and Layer 2 - Data Link layer. The Ethernet frames transmitted across the wire form Layer 2, and contents within is the Layer 3 IP packet, which in turn contains the Layer 4 TCP/UDP segment. –  icelava Sep 14 '10 at 8:58
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We buy all of ours. The cases when a selection of 6' and 15' cables can't fill a need are very, very few, and we'll crimp in those cases. I asked our Telecom people about this and their answer was:

We used to crimp all of our drop-cables ourselves. But we found that buying pre-made cables saved us a lot of time, especially when we're doing big areas. Also, we haven't had a problem with quality, and GigE is more sensitive to a bad crimp than 100Mb. So we just get off the shelf.

This is greatly helped by the fact that we don't have to run drop cables from the network rack to the server racks, we have sub-floor jacks positioned next to the server racks. THOSE cables are cut to length, of course. Because of this 7' and 15' cables work for the vast majority of our equipment-wiring needs.

I don't know what they do out in end-user-land. They probably have a wider selection of pre-made.

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I've been in both low-end and high-end "datacenters" recently. It all depends on how much time you have - and your budget.

In racks and patch bays, I would stress you use pre-made, and colored. We used one color for each of network devices, printers, servers, and then the blue for users and ip phones. Otherwise it will get messy in a hurry.

Everywhere else, it's up to you and your time. If you think your boss sees you as "idle" all the time, then crimp some cables in front of him/her and look busy... Your brain will turn to mush.

If you can I would spend your cycles learning more about the devices you are plugging in. That's what will pay your bills in the future. :)

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Not sure I understand the logic of not testing a cable you're just made "because they always say the cable I've made is ok." To me, the small amount of time it takes to test, even multiplied by the number of cables I've made over the years, is well worth the time saved diagnosing a resulting problem caused by the rare event that you missed a pin or crossed a wire, or that the length of cable you've just put ends on has a flaw.

For cat5/6, I'll use cables I've made both in the rack or an end run, but I test them first.

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depends for what. GE - always test of course. –  disserman Aug 13 '10 at 23:06
    
Fair enough, at home I might just crimp and plug I suppose. And to clarify, I'll only make at work if I need a specific length or if I'm feeling too impatient to order or buy. Which happens pretty often, so I must not be that patient. –  nedm Aug 15 '10 at 8:30
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When I was in my old job, I had this exact same question. We initially had our student assistants make all the cables we needed, but we realized that it took time and they hated it. Eventually, we started buying cables of standard length, but kept a spool and ends on hand for situations where we needed an exact length (or when the pre-made ran out). That ended up being a good solution because our students still got some experience working with cables, but they could spend more time focusing on doing real work.

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In the past, I've used pre-made cables for "short" cable runs (in a single rack or between nearby racks), while making cables that go any longer distance in under-floor cable channels.

Main reason for that is that it's much easier to get the cable in place pulling it from a well-designed cable box (or from a cable drum on a drum roller cradle) and not having to care about the connectors until the cable is actually in place.

But, unless you're doing quite a lot of "data centre"-type cabling, I'd say using pre-made cables is a better option, since you'd have to be pretty good at doing cables to make the time spent crimping them be less than the difference between cable and connectors.

Edit: Another reason for making cables is that most pre-made cables are not made fire-retardant and that's usually a requirement for any cable placed inside a wall of floor cavity (like data centre raised flooring).

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I prefer to buy my cables in different colours (depends on usage, for example in firewall or server) and always have the needed cable, connectors, tools, bridges for use when needed.

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There is some value in perfect-length cables in a rack environment, esp a high-density one. Allmost everything else turns to spaghetti.

As all the other posters posted, if a cheap standard length works: don't bother crimping.

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Where I work and have worked in the past it makes no sense to keep a large stock of cables of various lengths "just in case". It's very rare that I need more than a couple of cables at a time. When I need a cable I need it now, not when the next supplier delivery arrives, so I make them as required.

When doing one-offs I can make up a cable in much less time than I can create a purchase order, get it approved and placed. Cutting the cable to length, fitting 2 plugs and testing takes around 90 seconds (2 minutes on a bad day).

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You must have an expensive tester to have it test if it is cat3 vs cat5e vs cat6 that quickly. Mine takes almost a minute to run through the tests in cat6 mode. –  chris Aug 16 '10 at 20:14
    
I have no need to test what sort of cable it is. That information is printed on the cable itself. I only need to check the pairing and proper connectivity. That takes a few seconds. FWIW, the Fluke tester I used in my last job determined the cable type in about 10 seconds and that only cost less then $1K (AU). –  John Gardeniers Aug 16 '10 at 21:46
    
Wow. You're totally awesome. –  chris Aug 17 '10 at 0:53
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We generally buy cables, but there are some exceptions. My job includes deploying desktop hardware to end users, and often we don't have enough wall points to patch all of the computers and phones (we're not using a VOIP PABX yet), so we end up making converter cables to run 100Mb + phone over the same cable run.

Having a (relatively cheap) cable tester means we can check that we've crimped correctly, and also helps diagnose general network issues; sometimes wall sockets are damaged by a 6-pin modular plug on the end of a phone (which we'll re-crimp with an 8-pin plug), and it helps us rule out "bad cabling" vs. a misbehaving switch or desktop machine.

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Do you use a multi-thousand dollar fluke cable tester when you're making your cables? Or do you use one of those things with the 9volt battery that lights up red if the cable is mis-wired and green if it is properly wired?

Making a cat6 cable is actually pretty complex.

I've done it, but it requires proper tools and parts and most importantly, you need the tester. We've got one at work and after doing several, I can make cables that test out to cat6 in about 10 minutes per cable. Our tester is a cheap one ($5000 new a couple years ago) that takes about a minute to test the cable. The expensive ones test faster.

If you're just crimping the right pairs together and not testing, you could easily be making cat3 cables that kinda work but cause someone hours of troubleshooting later.

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can you explain what may happen if the cheap tester which only tests a pins says "all pins are connected" what may say the more expensive one? I've never had any bandwidth difference on a test systems using manually cropped cables as well as a pre-made. The bandwidth is always the same +/- 0.5-1%. –  disserman Aug 15 '10 at 21:22
    
Network cards aren't like modems -- if the connection is poor they won't scale back to a lower speed, instead you'll just get lots of garbled packets and then the application will have to retransmit the packet later at a substantial loss of speed. –  chris Aug 16 '10 at 20:09
    
As far as the cable tester -- you could run into situations where the link worked fine at 100mb and okay at gig without a large amount of traffic but when you try to use the system to push large amounts of traffic performance falls through the floor. –  chris Aug 16 '10 at 20:13
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For in-rack patching, I'd always go with buying cables off the shelf as it is cheaper and easier to buy them in. I'm a trained network engineer and my time is relatively expensive - I could be doing higher-value work such as configuring routers and switches. Another benefit of buying pre-made cables is that the quality of moulded-on strain-relief is better than anything that I can make myself, and if I buy them with anti-snag clips, it makes decommissioning so much easier, too. Have you ever timed yourself making and testing a cable and factored in your hourly-wage to figure out how much it really cost?

I am work in an environment with several thousand servers, and where we can afford to keep an inventory of various lengths in 6 colours. I can understand that if you don't have budget or storage space, then it would be useful to be able to make your own for an urgent job, but the few times I have made my own, they have been appalling quality. When I've bought in cables, I've rarely had any quality issues (only 2 duff new cables out of thousands I've used).

For infrastructure cabling (under floors, through ceilings) I would always get a cabling contractor to come in and manufacture a solution to length - these guys are crimping and punching down all day and will do a far better quality job. I can also ask them to do things like clearly label each end of the cabling, that I would never bother to do myself.

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