A Guide to Crimping RJ-45 Connectors

Crimping RJ-45 connectors onto CAT-5 cable can be frustrating. Some techniques make the

process of installing RJ-45 connectors easier.

Lesson one: Not all RJ-45 connectors are created equally. One reason why CAT-6 cable is

much harder to work with than CAT-5 cable is that CAT-6 is quite a bit thicker. So it's hard to get

RJ-45 connectors intended for CAT-5 cable to attach properly to CAT-6 cable. When you're

shopping for RJ-45 connectors, make sure the ones you buy are suitable for CAT-6. The picture

below shows a CAT-5 and a CAT-6 connector the CAT-6 connector is the darker one).

RJ-45 connectors intended for use with CAT-6 cable are larger than their CAT-5 counterparts. But even with the correct types of connectors, working with CAT-6 cable can be tough. Still, you can make the process easier. Begin by stripping the outer covering from the end of the cable. Remove about an inch of covering. Eventually you'll have to cut down the amount of exposed cable, but the process of installing the RJ-45 connector will be easier if you have plenty of exposed cable to work with (but not too much).

Once you remove the outer cover, you'll see that some of the pairs of wire are twisted together (hence the name twisted-pair cable). Untwist these wires. Once all the wires have been separated, pull them backward, as shown below, so you can cut off the exposed plastic core, as shown below. Remove as much of this core as you can. Be careful not to accidentally cut the wires in the process.

Now that the core has been removed, your next task is to straighten the wires that were previously twisted. The easiest way to do this is by using two pairs of tweezers. Use one set of tweezers to firmly hold the wire just beneath a bend, and the other pair to straighten the bend. The wires don't have to be perfectly straight, but the straighter they are, the easier your job will be.

Once you've straightened the wires, your next task is to arrange them in the order they'll be placed into the RJ-45 connector. Working from left to right, the order of the wires is:

 Orange with a white stripe

 Orange

 Green with a white stripe

 Blue

 Blue with a white stripe

 Green

 Brown with a white stripe

 Brown

Since the leftmost wire is the orange with the white stripe, there's a natural tendency to start with this wire on the left. Although it's possible to get the wires in the correct order using this technique, getting the wires to stay in order when you insert the RJ-45 connector becomes very difficult.

Rather than starting with the orange and white wire, lining up the wires is a lot easier if you start with the green wire with the white stripe, and then work on lining up the blue, blue and white, and green wires. When all is said and done, the wires will still have to be in the correct order, but starting with the green and white wire forces you to turn the cable a different direction than if you were initially working with the orange and white wire. This seems to make all the difference

in the world for getting the wires lined up in a way that facilitates easy installation of the RJ-45 connector.

Now that the wires are in the correct order, hold the RJ-45 connector next to the cable, as shown below, to determine how much wire needs to be cut off, as shown below. You'll want to make the cut so that the ends of the wires line up evenly. The proper length can be determined by looking at the cable's outer insulation. The insulation should stop just inside of the RJ-45 connector. It's better to make a series of small cuts to determine the appropriate cable length than to try to get it exactly right on the first cut. Test-fit the RJ-45 connector between each cut. If you try to get the length exactly right on the first cut, you risk cutting the wires too short.

The easiest way to slide the RJ-45 connector onto the cable is to use your thumb to apply pressure to the cable in the spot where the wires are first exposed from beneath the insulation. This will help keep the wires in order.

When the cable is finally cut to the correct length, you should check a few things before crimping the cable. First, make sure the wires go all the way to the end of the RJ-45 connector, as shown below. The easiest way to do this is to look at the end of the connector and make sure you see copper in each wire slot. This is difficult to photograph, the figure below shows that the wire goes all the way to the end of the connector.

You should also verify that the wires are still in the correct order. It's easy for the wires to get out of order when installing the cable end. A quick check at this point will keep you from having to cut the cable end off and starting over later.

Assuming the wires are in order, you can go ahead and crimp the cable. When you've finished crimping both cable ends, you can use a cable tester to verify that the ends were installed correctly.

How to Wire Keystone Jack

1
Strip about 1.5 inches of jacket from the twisted-pair cable
2
Separate the twisted wire pairs from each other; then un-twist each pair. Straighten wire ends out as much as possible
3
Remove the jack’s protective cap.
4
Once the cap has been removed, you’ll notice that there are wire configurations printed near the termination slots. If you are given a choice between “A” and “B” configurations, choose whichever one you’d like, just be sure to remember which one you’re using when it comes time to terminate the cable’s other end with a jack! Configurations must be the same at both ends of the network cabling.
5
Place all 8 wires into the center of the jack; from there, divert the wires into their correct slots, pressing them as far down into the termination slots as they will go. Excess wire length will be extending out of the sides of the jack.
6
It’s easiest to punch down wires if you do one side of the jack at a time. Make sure that the punchdown tool’s “Cut” side is aligned with the outer edge of the jack, and that the jack assembly is resting on a hard, sturdy surface that is able to withstand force. To punch down each wire, press down on thepunchdown tool until you hear a loud click and simultaneous, metallic-sounding “ping”. These noises are indicators that the punch-down has been done correctly; if you don’t hear them, you’ll know that the punchdown hasn’t been successful.
7
Check the quality of the punches. Inspect each termination slot along the outer edge of the jack; each wire should be firmly anchored at the bottom of its slot, and the wires’ copper conductors will be visible.
8
Snap the jack’s cover back on, over the wires .
9
Firmly insert the jack assembly into the faceplate from the back; be sure that the jack’s clip is facing up, so that it properly snaps into the faceplate port .
10
Screw the completed jack / faceplate assembly into the wall .

Wiring Tutorial for 10/100BaseT RJ45 Unshielded Twisted Pair (UTP)

One of the most common and most puzzling problems a network engineer/technician may face is what is the PROPER way to make up a 10/100BaseT cable. Usually, to confound the learning process, someone introduces the need for a reversed or cross-over cable at the same time. What these are and how to make them is the subject of this on-line tutorial.

This is most common cable for 10/100Base-T ethernet networks. This cable will work with both 10Base-T (10 Mbit ethernet) and 100Base-TX (100 Mbit ethernet) and is used to connect a network interface card to a hub or network outlet. Normally, there are 2 types of wiring. Both are correct.:

Selection of Cabling Category

Since the overwhelming bulk of network cabling done today uses Unshielded Twisted Pair (UTP) wiring that is what we will discuss. The process begins with the selection of the proper wiring level or category. Today it is basically inexcusable to use or install anything at less than Level V or Category 5.

While technically Category 5 and Level V are not the same, they are identical in practice. Both support upto 100 megabit per second data transmission, and their physical cable assembly requirements are the same. Throughout this tutorial we will refer to them both as CAT5.

When you order CAT5 unshielded twisted pair (UTP) cable you will receive a cable containing 4 twisted pairs of wires, a total of 8 wires. The strands that constitute each wire will either be a single strand or multiple strands, usually referred to as solid or flex. Typically the solid is used to run through walls and ceilings and the flex is used to make drop cables (the cable from the wall plate to the desktop computer) and patch cables (the cable from the patch panel to the hub). Whether the exterior portion of the cable that contains the 4 twisted pairs, the jacket, is Plenum grade or Non-plenum grade is very important, it refers to the Fire Codes, but is outside the scope of this tutorial.

Maximum Cable Length allowed is 329 feet.

Ordering Pairs

The pairs of wires in UTP cable are colored so that you can identify the same wire at each end. Furthermore, they are usually color coded by pair so that the pairs can also be identified from end to end. Typical CAT5 UTP cables contain 4 pairs made up of a solid color and the same solid color striped onto a white background. The most common color scheme is the one that corresponds to the Electronic Industry Association/Telecommunications Industry Association's Standard 568B.

The following table demonstrates the proper color scheme.

Wire pair #1:	White/Blue Blue
Wire pair #2:	White/Orange Orange
Wire pair #3:	White/Green Green
Wire pair #4:	White/Brown Brown

Connectors

The cable connectors and jacks that are most commonly used with CAT5 UTP cables are RJ45. The RJ simply means Registered Jack and the 45 designation specifies the pin numbering scheme. The connector is attached to the cable and the jack is the device that the connector plugs into, whether it is in the wall, the network interface card in the computer, or the hub.

Now that we are ready to insert the cable into the RJ45 plug the wire number and color sequence becomes more complicated.

The IEEE Specification for Ethernet 10BaseT requires that two twisted pairs be used and that one pair is connected to pins 1 and 2, and that the second pair is connected to pins 3 and 6. Yes that is right - pins 4 and 5 are skipped and are connected to one of the remaining twisted pairs.

According to the EIA/TIA-568B RJ-45 Wiring Scheme:

It gets even more odd because wire Pair#2 (white/orange, orange) and Pair#3 (white/green, green) are the only two pairs used for 10BaseT data.

Pair#2 is connected to pins 1 and 2 like this:
Pin 1 wire color:	white/orange
Pin 2 wire color:	orange
Pair#3 is connected to pins 3 and 6 like this:
Pin 3 wire color:	white/green
Pin 6 wire color:	green

The remaining two twisted pairs are connected as such:

Pair#1
Pin 4 wire color:	blue
Pin 5 wire color:	white/blue
Pair#4
Pin 7 wire color:	white/brown
Pin 8 wire color:	brown

This is illustrated in the following diagram: 568B standard

Now the wires forming the pairs must be gathered together and trimmed so that they can be inserted into the RJ45 plug. The pairs gathered and trimmed is illustrated in the following diagram:

Then when the pairs are inserted into the RJ45 plug they should look like this:

---

Crossover Cables

In order to make what is commonly referred to as a "Crossover" cable one must change the pinout connections on ONE end of the cable. If you do it on both ends of the cable you have crossed-over the crossover and now have a straight-through cable, albeit a very non-standard one. In this case two negatives do make a positive.

You need to make a cable where pins 1 & 2 from one end are connected to pins 3 & 6 on the other end, and pins 3 & 6 from the first end are connected to pins 1 & 2 on the other end. Pins 4 & 5 and 7 & 8 are unchanged.

The two ends look like this:

     Standard End                          Crossover End

       Pin 1 White/Orange                   Pin 1 White/Green

       Pin 2 Orange                         Pin 2 Green

       Pin 3 White/Green                    Pin 3 White/Orange

       Pin 4 Blue                           Pin 4 Blue

       Pin 5 White/Blue                     Pin 5 White/Blue

       Pin 6 Green                          Pin 6 Orange

       Pin 7 White/Brown                    Pin 7 White/Brown
 
       Pin 8 Brown                          Pin 8 Brown

The following is the proper pin out and cable pair/color order for the "crossover" end.

Pair#2 is connected to pins 1 and 2 like this:
Pin 1 wire color:	white/green
Pin 2 wire color:	green
Pair#3 is connected to pins 3 and 6 like this:
Pin 3 wire color:	white/orange
Pin 6 wire color:	orange

The crossover pairs are illustrated in the following diagram:

Then when the pairs are inserted into the RJ45 plug they should look like this:

Note: Even though we are only interested in attaching the connectors to the cable in this tutorial, we must take into account the wiring of the jacks as well so that we connect the proper wires from the cable to the proper pins in the connectors. And that is determined by the wiring in the jack the connectors will be plugged into.

RJ45 Wall jack

Most wall jacks come with a wiring diagram or numbered pins.

T568A and T568B

T568 A or T568 B Wiring Schemes- What's the Difference?

Based on TIA/EIA-568-B.1-2001, the T568A and T568B wiring schemes define the pinout, or order of connections, for wires in eight-pin modular connector plugs and jacks.

The only difference between T568A and T568B is that pairs 2 and 3 (orange and green) are swapped. Both configurations wire the pins "straight through", i.e., pins 1 through 8 on one end are connected to pins 1 through 8 on the other end, and the same sets of pins are paired in both configurations: pins 1 and 2 form a pair, as do 3 and 6, 4 and 5 and 7 and 8.

Cables that are terminated with differing standards on each end will not function normally, however mixing T568A-terminated patch cords with T568B-terminated horizontal cables (or the reverse) will not produce pinout problems in a facility, although it may slightly degrade signal quality, This effect is marginal and certainly no greater than that produced by mixing cable brands in-channel.

T568 A or T568 B- Which One Should I Use?

• If the installation is residential, choose T568A unless other conditions apply (see below).
• If there is pre-existing voice/data wiring (remodel, moves, adds, changes), duplicate this wiring scheme on any new connection.
• If project specifications are available, use the specified wiring configuration.
• If components used within the project are internally wired either T568A or T568B, duplicate this wiring scheme.

T568A and T568B Wiring Assignments:

Wiring Standards

Pin #	T568B	T568A
1	White/Orange	White/Green
2	Orange	Green
3	White/Green	White/Orange
4	Blue	Blue
5	White/Blue	White/Blue
6	Green	Orange
7	White/Brown	White/Brown
8	Brown	Brown

Ethernet Cable Tips

A straight-thru cable has identical ends.

A crossover cable has different ends.

A straight-thru is used as a patch cord in Ethernet connections.

A crossover is used to connect two Ethernet devices without a hub or for connecting two hubs.

A crossover has one end with the Orange set of wires switched with the Green set.

Odd numbered pins are always striped, even numbered pins are always solid colored.

Looking at the RJ-45 with the clip facing away from you, Brown is always on the right, and pin 1 is on the left.

No more than 1/2" of the Ethernet cable should be untwisted otherwise it will be susceptible to crosstalk.

Do not deform, do not bend, do not stretch, do not staple, do not run parallel with power cables, and do not run Ethernet cables near noise inducing components.

Crimp an RJ-45 Jack onto a Cat5e cable

RJ45

RJ45

RJ45 is a type of connector commonly used forEthernet networking. It looks similar to a telephone jack, but is slightly wider. Since Ethernet cables have an RJ45 connector on each end, Ethernet cables are sometimes also called RJ45 cables.

The "RJ" in RJ45 stands for "registered jack," since it is a standardized networking interface. The "45" simply refers to the number of the interface standard. Each RJ45 connector has eight pins, which means an RJ45 cable contains eight separate wires. If you look closely at the end of an Ethernet cable, you can actually see the eight wires, which are each a different color. Four of them are solid colors, while the other four are striped.

RJ45 cables can be wired in two different ways. One version is called T-568A and the other is T-568B. These wiring standards are listed below:

T-568A White/Green (Receive +) Green (Receive -) White/Orange (Transmit +) Blue White/Blue Orange (Transmit -) White/Brown Brown

T-568B White/Orange (Transmit +) Orange (Transmit -) White/Green (Receive +) Blue White/Blue Green (Receive -) White/Brown Brown

The T-568B wiring scheme is by far the most common, though many devices support the T-568A wiring scheme as well. Some networking applications require a crossover Ethernet cable, which has a T-568A connector on one end and a T-568B connector on the other. This type of cable is typically used for direct computer-to-computer connections when there is no router, hub, orswitch available.
 is the common name for an 8P8C modular connector using Niranjan Malwade that was also used for both RJ48 and RJ61 registered jacks (which specify pin assignments of the wires in a telephone cable), although "RJ45" was not originally specified as a registered jack with today's Ethernet wiring. The "RJ45" physical connector is standardised as the IEC 60603-7 8P8C modular connector with different "categories" of performance, with all eight conductors present but 8P8C is commonly known as RJ45. The physical dimensions of the male and female connectors are specified in ANSI/TIA-1096-A and ISO-8877 standards and normally wired to the T568A and T568B pinouts specified in the TIA/EIA-568 standard to be compatible with both telephone and Ethernet.

A similar standard jack once used for modem/data connections, the RJ45S, used a "keyed" variety of the 8P8C body with an extra tab that prevents it mating with other connectors; the visual difference compared to the more common 8P8C is subtle, but it is a different connector. The original RJ45S keyed 8P2C modular connector had pins 5 and 4 wired for tip and ring of a single telephone line and pins 7 and 8 shorting a programming resistor, but is obsolete today.

Electronics catalogs commonly advertise 8P8C modular connectors as "RJ45". An installer can wire the jack to any pin-out or use it as part of a generic structured cabling system such as ISO/IEC 15018 or ISO/IEC 11801 using RJ45 patch panels for both phone and data. Virtually all electronic equipment which uses an 8P8C connector (or possibly any 8P connector at all) will document it as an "RJ45" connector.

Crossover cables

A router to router crossover cable uses two 8 position connectors and a UTP (Unshielded Twisted Pair) cable with differently wired connectors at each end. Although a registered jack specifies the wiring pattern and corresponding form factor rather than just the pin assignments or the physical connector, crossover cables are often incorrectly marketed as "RJ45 crossover cables".