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How to make a category 5E Patch
Cable |
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Introduction:
Due to an overwhelming response to our category 5E
tutorial, and many requests for information and wiring diagrams of "straight
through" and "crossover" (cross-pinned) patch cords, I have made this
informational page. On this page, we will cover making patch cords, and
other technical and non-technical issues relating to category 5 (and beyond)
patching and connectivity from device to device. Below, you will find the
diagrams for 568A, 568B, and crossover patch cables. I suggest that you read on,
past the diagrams for some very useful and important information.
As always, there continues to be Controversies over standards and
practices regarding the use and making of patch cords, and UTP cable in general.
Please see our section below titled: "Controversies and Caveats : Category 5,
5E, and Cat 6 Patch Cables". I hope that you will find it interesting and
informative.
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568-B Wiring |
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568-A Wiring |
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Pair # |
Wire |
Pin # |
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1 - White/Blue |
White/Blue |
5 |
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Blue/White |
4 |
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2 - White/Orange |
White/Orange |
1 |
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Orange White |
2 |
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3 - White/Green |
White/Green |
3 |
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Green/White |
6 |
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4 - White/Brown |
White/Brown |
7 |
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Brown/White |
8 |
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<<
568-B Diagram |
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Pair # |
Wire |
Pin # |
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1 - White/Blue |
White/Blue |
5 |
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Blue/White |
4 |
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2 - White/Green |
White/Green |
1 |
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Green/White |
2 |
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3 - White/Orange |
White/Orange |
3 |
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Orange/White |
6 |
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4 - White/Brown |
White/Brown |
7 |
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Brown/White |
8 |
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<< 568-A
Diagram |
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Notes for wiring diagrams above:
1. For patch cables, 568-B wiring
is by far, the most common method.
2. There is no difference in
connectivity between 568B and 568A cables. Either wiring should work fine
on any system*. (*see notes below)
3. For a straight through cable, wire both ends identical.
4.
For a
crossover cable, wire one end 568A and the
other end 568B.
5. Do not
confuse pair numbers with pin numbers. A pair number is
used for reference only (eg: 10BaseT Ethernet uses pairs 2 & 3). The
pin numbers indicate actual physical locations on the plug and jack.
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Patch Cable Assembly
Instructions |
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1) Skin off the cable jacket
approximately 1" or slightly more.
2)
Un-twist each pair, and straighten each wire between the fingers.
3)
Place the wires in the order of one of the
two diagrams shown above (568B or 568A). Bring all of the wires together,
until they touch.
4) At this point,
recheck the wiring sequence with the diagram.
5) Optional: Make a mark on the wires at 1/2"
from the end of the cable jacket. |
8) Insert the wires into the
connector (pins facing up). |
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6) Hold the grouped (and sorted)
wires together tightly, between the thumb, and the forefinger.
7) Cut all of the wires at a perfect
90 degree angle from the cable at 1/2" from the end of the cable jacket.
This is a very critical step. If the wires are not cut straight, they may
not all make contact. We suggest using a pair of scissors for this
purpose. |
9) Push moderately hard to assure
that all of the wires have reached the end of the connector. Be sure that
the cable jacket goes into the back of the connector by about
3/16". |
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7B) Conductors should be at a
straight 90 degree angle, and be 1/2" long, prior to insertion into the
connector. |
9) Place the connector into a crimp
tool, and squeeze hard so that the handle reaches it's full swing.
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10) Repeat the
process on the other end. For a straight through cable, use the same
wiring. For a "crossover" cable, wire one end
568A, and the other end 568B.
11) Use a cable tester
to test for proper continuity. |
Notes Regarding Making Category 5 Patch Cable |
| 1) |
The RJ-45 plugs are normally made for either solid
conductors or stranded conductors. It is very important to be sure that
the plug that you use matches the conductor type. It is extremely
difficult to tell the difference between the two by looking at them. When
you buy these plugs, be sure to categorize, and store them carefully.
Using the wrong type can cause intermittent problems. The
RJ-45, 8 Conductor Plugs that we sell are rated for both Solid and
Stranded cable. |
| 2) |
Ordinarily, it would be taboo to untwist the pairs of any
category 5 cable. The one exception to this rule is when crimping on RJ-45
plugs. It would be impossible to insert the wires into the channels
without first untwisting and straightening them. Be sure not
to extend the un-twisting, past the skin point. If you do it
properly, you will wind up with no more than 1/2" of untwisted conductors
(up to 1/2" of untwist meets the cat 5 specification) |
| 3) |
If the completed assembly does not pass continuity, you
may have a problem in one, or both ends. First try giving each end another
crimp. If that does not work, then carefully examine each end. Are the
wires in the proper order? Do all of the wires fully extend to the end of
the connector? Are all of the pins pushed down fully. Cut off the
suspected bad connector, and re-terminate it. If you still have a problem,
then repeat the process, this time giving more scrutiny to the end that
was not replaced. |
| 4) |
It is good to be prepared to make your own patch cables.
There may be many instances where you may fall short on supply, and making
a cable will surely get you out of a jam. However, there comes a point
where the practicality curve will lead you to factory made cables. Making
several cables can be very labor intense. Factory made cables typically
have better tolerances, and consequently have better quality than field
made cables. |
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Controversies and
Caveats : Category 5, 5E, and Cat 6 Patch
Cables |
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568B vs.
568A |
For patch cables, 568-B wiring is by
far, the most common wiring method. Virtually all pre-assembled patch
cables are wired to the B standard. There is no
difference in connectivity between 568B and 568A cables.
Therefore, a 568B patch cable should work fine on a 568A cabling system,
and visa-versa. To my knowledge, there has never been an issue with
networks of up to 100 megabits. However, with the advent of Gigabit
over copper cabling, it may very well become a factor at some point.
We have conferred with several cable manufacturers, and many other
technical resources, on this subject. The consensus is that mixing of the
standards on patch cables should not cause a problem. Since Gigabit
networks over copper cabling are in their infancy, and no one can say for
sure, we would advise our customers to take the safe approach on all
future patch cable orders. We now offer our custom cat 5E and category 6
cables in both 568A and 568B wiring schemes for this reason. |
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Re-use of old
cables |
We have seen this happen time and time again. Perfectly
good patch cables that have been working fine for years, get removed from
their installation, and re-installed on the same, or different network.
The result can be a nightmare. What happens is that the cable, over
time, adapts to the way that it is bent in it's original
installation. When these cables are removed and re-installed, they can
either completely loose their connection, or develop intermittent
problems. This is due to stresses that may be opposite to what they were
originally subject to. If the integrity of your network is more valuable
than the price of new patch cables, then we strongly suggest that you use
brand new cables for all closet cleanups, network moves, etc. |
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Stranded
vs. Solid wire |
Almost all patch cables that are made have stranded
wire. Stranded wire is normally specified for use in patch cables due to
it's superior flexibility. There has been some talk recently, in the
technical sector of the structured wiring community, regarding the possible
use of solid conductors for patch cables. The reason for the spotlight on
solid wire is that it is supposedly more stable, under a variety of
conditions. |
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