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I had a naff batch of cat5 connectors (the latching mechanism didn't work) so decided to order in some cat6 connectors in preparation for the inevitable upgrade.

My existing reel of for making patch cables is cat5e utp stranded. I made up a few cables and tested them- none of them worked. I recrimped and still nothing. When i check them with a multi-meter not all pins are connected.

This reel has always worked with the previous cat5 connectors so I tested the cat6 connectors on a reel of solid cat5e cable and they work fine.

Any ideas what I might be doing wrong? Or what might be at fault? (cable/connectors) and how I can diagnose?



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This doesn't really answer your question, but making your own cables is likely a waste of time/money. See here for a nice explanation: everythingsysadmin.com/2011/01/… –  ThatGraemeGuy Jan 16 '12 at 10:31
isn't cat6 grounded using the braid around the cable pairs ? –  Sirex Jan 16 '12 at 10:37
What's the difference between a CAT5 connector and a CAT6 connector, other than the label on the package? CAT6 uses the same 8P8C connector that CAT5 does as far as I know. In addition, what inevitable upgrade are you referring to? GbE will run just fine on CAT5 and CAT5e cable. Are you upgrading to 10GbE? –  joeqwerty Jan 16 '12 at 11:40
cat5 connectors are a single piece (the cores are all aligned in a single horizontal line). cat6 connectors come as two pieces- a guide rail which you load the 8 cores into before loading into the outer shell and crimping (the cores are aligned in 2 rows of 4) –  Lee Tickett Jan 16 '12 at 11:45
and yes- progressively as prices come down and as my existing supplies run out i will order in higher standard equipment (so i don't have to replace everything at once). also i may be running HDMI over cat (which may require cat6) etc –  Lee Tickett Jan 16 '12 at 11:50

8 Answers 8

I've hand-crimped hundreds, maybe thousands of patch cables. The thing that normally bites you is trying to use modular plugs designed for stranded wire on solid conductor cable or vise versa. They have to match. If not, you'll get enough connectivity for a DVM to show that your pinouts are correct, but not enough to support a 100Mhz signal.

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Cat6 has larger diameter individual conductors as opposed to cat5. You are using cat6 connectors on the smaller diameter cat5. That is most likely your issue. Tolerances on the rj45 connectors are very marginal. If they were compatable with every kind of cable they wouldnt sell different connectors for specific cables. My guess is you got a lucky crimp on a solid cat5 cable. I have heard of people doing this to cut costs. The bottom line is if you want cables with quality connections you cant cut corners and mismatch connectors.

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Compared with Cat 5 and Cat 5e, Cat 6 has more stringent specifications for crosstalk and system noise. Additionally, stranded cable has higher attenuation than solid cable. In my opinion, this is what bit you, assuming that you've ordered connectors that are compatible to stranded cable (and not to solid cable), which would've been my first guess otherwise.

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up vote 1 down vote accepted

So it turns out that cat6 connectors are not neccessarily backwards compatible with cat5(e) cable. I'm struggling to find sources to cite at the moment- http://www.cat6.com/faqs/freqAskQues%20cabling%20system.aspx for example suggests they are backward compatible- lots of confusion!

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The company we used told me a story of a job they did when they first started using a new set of Cat6 clip-shut terminals. They had connected 1000's of cables to a giant patch panel and they all failed because the clippers they had used did not clip the ends of the cables precisely flush and so 1mm of cable was poking out and when the metal terminal was clipped shut, all the cables touched the metal case and so shorted.

Once they worked out the problem it was simply a matter of getting some better clippers and clipping the 1000's of cables exactly flush and they all worked a treat.

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I faced the same problem as yours, but when I got solution then I came to know 'how stupid am I'.

The solution is 568-B Wiring on both ends. This applies to Cat6 as well. Check out the article How to Make a Category 5 / Cat 5E Patch Cable.

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While the cables and connectors look very similar, there's a difference. Category 6 uses thicker 22 AWG wire, while Category 5 uses thinner 24 or 26 AWG wire. This causes two different problems:

The smaller wire pairs (CAT5) aren't large enough to securely fit in the connectors made for the larger wire pairs (CAT6). You can tell a CAT6 connector by the fact that the wires are staggered at the end of the connector, so that 4 pairs of larger wires will fit.

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The second issue is that the conductors in CAT5 RJ45 ends are generally not strong enough to pierce the thicker insulation as well as the thicker wire in CAT6 cables. So even if you can physically fit the cables, you won't get a quality connection.

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In response to Max. Wiring methods really mean nothing on a patch cable. Patch cable meaning it has male connectors on both ends,your using it as a link between 2 female ports. The only thing that matters are both ends are terminated the same. However you land each pair on one end must be exactly the same on the other. Dont think of it as a colour order, you simply need to link each rj45 pin with the other end.. pin 1 to pin 1... 2 to pin 2 etc.. Electricity cares not which colour the insulation of its conductor is. If you were mass producing cables you could save alot of time by not having to re-arrange conductors for every rj45 termination. In fact alot of cables you buy are punched down in this manner. Ive seen many manufactured cables like this.

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That was the most horrible answer I have seen in a while. There is a reason for official standards as T568A/B that minimizes the crosstalk in the cable. –  Frederik Nielsen Nov 28 '14 at 17:16

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