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1.12 Cat 5 Wiring

According to ANSI/TIA/EIA-568-A standard, "horizontal wiring" from a wiring closet to the outlet should be 90 meters or less, plus another 3 meters for a patch cord to the workstation. In round numbers, that's about 300 feet.

If you plan to connect between buildings with different power sources, or go beyond 300 feet, you should consider using fiberoptic line with a media converter at each end.
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by DTVtech

by KeysCapt See Profile
last modified: 2002-07-22 22:56:59

TIA/EIA-568A and -568B are two standards for connecting Category 3 and Category 5 wire to connectors. Both are appropriate for high speed data, though 568B is somewhat more common for installed wiring and 568A is more common in jumpers. There is no performance advantage either way. The only real difference between the two is the order in which the pairs are used (orange and green).

Hold a cable as if to plug it into a wall jack, the locking tab down (contacts facing you). The contacts are numbered 1-8 from left to right. Here's what you will see:

EIA/TIA-568A:
Pin 1: White/Green
Pin 2: Green/White (or just plain Green)
Pin 3: White/Orange
Pin 4: Blue/White (or just plain Blue)
Pin 5: White/Blue
Pin 6: Orange/White (or just plain Orange)
Pin 7: White/Brown
Pin 8: Brown/White (or just plain Brown)

EIA/TIA-568B:
Pin 1: White/Orange
Pin 2: Orange/White (or just plain Orange)
Pin 3: White/Green
Pin 4: Blue/White (or just plain Blue)
Pin 5: White/Blue
Pin 6: Green/White (or just plain Green)
Pin 7: White/Brown
Pin 8: Brown/White (or just plain Brown)

568A and 568B may be used interchangeably in a system SO LONG AS both ends of a given cable are terminated the same way.
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by DTVtech

by KeysCapt See Profile
last modified: 2002-07-22 22:58:23


There are some couplers out there designed for category 5 wiring, but most are not -- they're mostly intended for extending cellular and business phone sets. And it isn't always apparent which are which.

In general, you are better off using one cable of the right length than joining several together.
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by DTVtech

by KeysCapt See Profile
last modified: 2002-07-22 22:59:35

They provide some strain relief (so the wire doesn't pop out of the connection) and keep dirt and moisture out. They are not a replacement for using a proper punchdown tool to make the wire connection.
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by DTVtech

by KeysCapt See Profile
last modified: 2002-07-22 23:01:12

There are two varieties of category 5 wire that should be used: one has solid conductors and is generally used for permanent wiring; the other has stranded conductors and is generally used for making flexible patch cords. Some RJ-45 plugs are designed for solid wire (their contacts straddle each conductor), others are designed for stranded wire (and pierce through between of the strands). Using the wrong type of plug for a given type of cable will make a poor connection that may fail intermittently. There is a third variety of RJ-45 plug that will work with either solid or stranded wire.

Another cause of bad crimp connections is using the wrong crimping tool for a given brand of connector. In particular, many AMP brand connectors have the strain reliefs located in a different position than most. Using a standard tool with these plugs will damage the plug.

Ensure that the wires when cut are of equal length and pushed all the way up into the plug so the copper is flush at the top.
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Added by an anonymous member:
Solid CAT5 wire which is cheaper and used to span any appreciable distance must use IDC (Insulation Displacement Connectors) using a punchdown tool at the patch panel or jack. Solid wire is also much more efficient at transmitting data. Stranded CAT5 wire must use IPC (Insulation Peircing Connectors) and is used for the short distance from patch panel to network switch or device or computer, thus the term 'patch cable'. Therefore, solid wire IDC terminations should always result in an impact tool IDC connection in a CAT5 JACK. Stranded wire IPC terminations should always result in a compression IPC connection in a CAT5 PLUG. The length of untwisted pair may not exceed one half inch at the plug, and twist should be maintained all the way to connection point on the jack. Solid wire connections, once installed, should never be disturbed. Ensure that the outer jacket of the UTP cable is crimped within the RJ45 plug to provide strain relief.

by DTVtech and outkast7621


Feedback received on this FAQ entry:
  • The second post is not correct that "Stranded CAT5 wire must use IPC". Patch panels have IDC (not IPC) terminals and these are almost always Universal IDC - that is they are specified for use with either solid OR stranded core. Plugs are another matter. As the first post rightly says, plugs with a single blade will just cut into a solid core instead of pushing between strands. The harder you press on the crimp tool the more likely you are to damage the wire.

    2009-08-25 21:07:15

  • Solid CAT5 wire which is cheaper and used to span any appreciable distance must use IDC (insulation Displacement connectors)using a punchdown tool, at the patch panel,or jack. Solid wire is also much more efficient at transmitting data. Stranded CAT5 wire must use IPC (insulation Peircing connectors) and is used for the short distance from patch panel to netwok switch or device or computer, thus the term (patch cable). Therefore, solid wire IDC terminations should always result in a impact tool IDC connection in a CAT5 JACK. Stranded wire IPC terminations should always result in a compression IPC connection in a CAT5 PLUG. The length of untwisted pair may not exceed one half inch at the plug, and twist should be mantained all the way to connection point on the jack. Solid wire connections, once installed, should never be disturbed. Make sure the outer jacket of the UTP cable is crimped within the RJ45 plug to provide strain relief.

    2009-03-13 20:11:54

by KeysCapt See Profile
last modified: 2009-03-14 09:57:36

They look nice, and the companies that make patch cables can sell them for more money. Also, when you pull a cable back through a nest of other wires the boot keeps the locking tab on the plug from getting snagged and broken off. (That probably isn't a big concern for most home networks!)

Do boots keep dust out? Possibly, but a jack with a plug in it shouldn't be getting stuff in there anyway... it's the empty jacks that collect lint.
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by DTVtech

by KeysCapt See Profile
last modified: 2002-07-22 23:03:04

Plenum rated cable is required by some fire codes if you run wiring in locations where the HVAC system moves air -- above suspended ceilings and through cold air returns, for instance. This cable is designed to withstand higher temperatures than ordinary PVC jacketing and burns less readily than PVC. For most homeowners, plenum rated cable is probably not necessary and typically costs 2-3 times more than PVC. There is no electrical difference between the two, and either will perform equally well.
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by DTVtech

by KeysCapt See Profile
last modified: 2002-07-23 00:57:57

Each network cable contains four pairs of wire, each pair twisted at a regular rate. Better grades of cable deliberately apply different amounts of twist to each pair. 10-Base-T and 100-Base-T lines use two pairs, one to transmit and one to receive data, copper Gigabit uses all four pairs. The twists provide a consistent impedance along the length of the cable, reduce the crosstalk between pairs and tend to make induced noise cancel out.

To preserve these qualities, it is important to maintain the twist when installing connectors, right up to the point of termination. You shouldn't untwist more than about a half an inch of wire. And when you install the cable, take care not to pull it tightly or make sharp bends, as those will disrupt the pairs' integrity.
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by DTVtech

by KeysCapt See Profile
last modified: 2002-07-23 00:57:30

Both are "punchdown" blocks used to interconnect voice and data systems in an orderly way. Type 66 blocks have been around longer and were developed for the phone company; they make it easy to connect multiple phone taps to a given line, and with the use of bridging clips provide an easy way to disconnect inside wiring from a circuit for troubleshooting. Older 66 blocks are not suitable for category 5 wiring, although several manufacturers have come out with revised 66 blocks that will work.

110 blocks are newer and are preferable for computer work: for one thing, they make it easier to preserve the twist in each pair right up to the point of connection. Most Category 5 jacks also use type 110 terminals for connecting to the wire.

A traditional impact punchdown tool with interchangeable bits like a Harris/Dracon will cost about $75 and can punch either 66 or 110 blocks (or any number of other types). Less expensive impact tools without interchangeable bits run about $25. Both kinds of impact tools both connect and trim the wire to the correct length. For a couple of bucks you can get a plastic tool for 110 blocks that might get you by for a few connections, but it won't trim the wire. Personally, I would stick with an impact tool.
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by DTVtech

by KeysCapt See Profile
last modified: 2002-07-22 23:05:32

Coax is always better than twisted pair. The 10base2 is a limited by the equipment on either end of the cable. The cable has a very high bandwidth capability, if the proper equipment is attached on either end. If you look at it from a very narrow data persons point of view, not an electronics person, 10base2 is slower than cat 5 cable. Cat 5 cable won't come close to RG-58.

By NickNielsen
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Member Comment:

One should qualify what "better" means in this context. Cat 5 cables are "better" if light weight, low cost and flexibility are important. Cat 5 cables are "better" if one doesn't want to deal with TNC connector hardware and cable terminators. If achieving the highest speeds over longer distances is more important, then coaxial cable is "better"
From DSLR member fivebyfive See Profile


Feedback received on this FAQ entry:
  • I install Commercial Security Systems and was on one particular job where there was RG58 cable everywhere (since abandoned) This building was formerly Westinghouse R&D in Pittsburgh. They did a lot of research on Nuclear Reactors and even though Cat5e was available even then, the cable was needed for extreme speed from Mainframes to Workstations (some were Silicon Graphics) and I think they had a couple of Cray's in the Data Room as it had some heavy duty A/C. None of this was there now and the building is now a Business Telecom Company with some former employees still onboard telling me they did a lot of 3D real-time modeling and simulations. That would of been something to see. But they chose Cable over Cat5e for the speed and might of went with fiber but that was just starting to evolve then (around 1980-90s)

    2014-03-12 11:59:30

by KeysCapt See Profile
last modified: 2008-01-10 17:19:02

Cat-5e is enhanced Cat-5 cable. The only difference between the two UTP cables is the tested signal level. Cat-5e is tested at a higher frequency or signal level than regular Cat-5. You could find Cat-5 and Cat-5e anywhere for about the same price. Getting Cat-5e means you are getting cable that is tested under higher standards.

by brianhn1 See Profile edited by KeysCapt See Profile
last modified: 2003-02-18 19:32:04

A crossed ethernet cable is used for communication between two computers without using network gear such as a router, switch or a hub.

To identify a cross-over ethernet cable, hold one end as if to plug it into a wall jack, the locking tab down (contacts facing you). The contacts are numbered 1-8 from left to right. One end will have a different color sequence to the other. A crossover cable, like a straight through cable, works both ways.

Using the 568B standard, the wiring sequence for ONE end (that may be labeled T-568B):

PIN 1 - White/orange
PIN 2 - orange
PIN 3 - white/green
PIN 4 - blue
PIN 5 - white/blue
PIN 6 - green
PIN 7 - white/brown
PIN 8 - brown

The for the OTHER end (that may be labeled T-568A):

PIN 1 - White/green
PIN 2 - green
PIN 3 - white/orange
PIN 4 - white/brown
PIN 5 - brown
PIN 6 - orange
PIN 7 - blue
PIN 8 - white/blue

If both ends have the same color sequence (usually T-568A, but it doesn't really matter), it is a straight-through cable.


Feedback received on this FAQ entry:
  • Pins 4 and Pins 5 are always blue/white blue, for legacy voice transmission. Pins 7 and 8 are always white/white-brown In a crossover cable pins 1 and 3 , and pins 2 and 6 are reversed! The T568b is correct but not the T568A!

    2014-12-21 20:12:12

  • or just try it if it works its a straight through and if it doesn't its a crossover cable.

    2011-05-16 21:51:46

by stephen d8 See Profile
last modified: 2007-05-16 14:55:20


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