RJ45 Colors and Wiring Guide Diagram-TIA / EIA 568 A B


If you’ve ever installed a network, either for your home, office or business, you’ve probably asked yourself- With so many different types of network cabling, what do I really need?  Is it a CAT5, 5E, 6, 6A, shielded or unshielded, UTP or STP? Do I need a patch/straight through cable or a crossover cable?  With so many different kinds of network cables to choose from, which one is right for your needs?

What types of network cable are available currently?

Cat5 has been replaced by Cat5E as the general standard networking cable in new installations, with the improved signal carrying capacity being the primary reason.  A Cat5 cable can support Ethernet and Fast Ethernet. Cat5E (Cat5 enhanced) supports Ethernet, Fast Ethernet, and Gigabit Ethernet speeds over short distances and is backward compatible with Cat5.  Cat5E cable also has improved durability, due to improvements in the quality of the PVC protective jacket. It is more than suitable for most data cabling requirements.

Cat6 is one of the newest versions of network cabling, and is very similar to Cat5E, but specifically designed to consistently deliver 1 Gigabit Ethernet. It is used in installations where a Cat6 Certified Network is required.

While Cat5E and Cat6 can support Gigabit speeds, Cat6A (Cat6 Augmented) is certified to 10 Gigabit speeds and is backward compatible with the all the existing standards, and is suitable for industries utilizing high-performance computing platforms to support very high bandwidth-intensive applications. 10G/Cat 6A applications would be server farms, storage area networks, data centers & riser backbones.

Table 1: Overview of Ethernet Cables

**** All cables are backwards compatible, meaning the higher categories can work with the lower categories of Ethernet.For Example the CAT6A can work in place of a CAT5E if needed. We currently do not carry the CAT5 rated cable as the CAT5E has essentially rendered it obsolete. The illustrations below exaggerate typical uses.

What is the difference between stranded, solid cable, and plenum rated cables?

Cat 5E, 6 and 6a can all be purchased in stranded or solid, and/or plenum wire construction. Stranded or UTP (Unshielded Twisted Pair) is primarily used for patch cables. The core of the cable is comprised of insulated strands of copper so that it can be flexed repeatedly without the copper cores of the conductors breaking. Solid Cat5E is primarily used for in wall/permanent applications. The cable cores are comprised of one single solid strand of copper. This allows the cable to carry signals over longer distances but cannot be flexed too many times without the copper cores breaking. Plenum is primarily used for in wall/permanent applications where the local building codes require its use as the low smoke/flame retardant jacket reduces the amount of toxic fumes that are released into air when the jacket is burned.

 Table 2: Construction of Ethernet Cables

**** Our Cables and Kits.com Patch Cables are mostly comprised of Snagless (Booted) Stranded UTP cables. Our listings do not explicitly list Stranded UTP, however if the cable is Solid or Plenum rated, this will be indicated in the description.

What is the difference between a patch or straight through cable, shielded cable and a crossover cable?

Patch or Straight through cables, are used to connect almost all networking components together and are the most common cable as a result. Some examples of connections made with patch cables would include:

• Patch Panel to Computer
• Computer to DSL/Cable Modem
• Computer to Hub
• DSL/Cable Modem to Router
• DSL/Cable Modem to Hub
• DSL/Cable Modem to Wireless Access Point
• Wall Plate to Computer

Crossover cables are used in situations where two devices have the same interface, for example, connecting a hub to a hub, or a switch to a switch, or patching a hub or switch into a wall plate. Some examples of connections made with crossover cables would include:

• Switch to Switch
• Computer to Computer (peer-to-peer network)
• Hub to Hub
• Access point to Access point

These types of cables also come in shielded versions. Shielded Cable or STP (Shielded Twisted Pair) has a protective “foil” that surrounds the cable. Shielded cable was designed to prevent strong sources of Electromagnetic Interference (EMI) and Radio Frequency Interference (RFI), from affecting the ability of the cable to transmit data. Generators, Elevator motors, and many types of lighting will produce strong EMI that can pass through the cable, corrupting your data and shutting down communication. The shielding in the wire blocks this energy from getting through.

Table3: Different Types of Connectivity

**** The cables listed on Cables And Kits.com are listed as “Patch Cables” and Straight Through type cables. Crossover will be listed as “Crossover” and Shielded STP will be listed as “Shielded”.

So, what kind of network cable is best for you?

For most home and office applications, Cat5E should suit your purposes- using solid wire in the walls and ceilings, twisted wire patch cables for your computers, routers, modems and peripherals, and crossover cables between switches, access points, and patch panels where required. Cat6 and Cat6A could be used in to order to establish a large network of high speed servers or data centers or to “future proof” new installations where growth or upgrades of your equipment capacities is a high possibility. Network cables are the backbone of any network and choosing the correct ones will increase your network’s communication, efficiency and cost effectiveness.

Ethernet Cable Tips:

  1. A straight-thru cable has identical ends.
  2. A crossover cable has different ends.
  3. A straight-thru is used as a patch cord in Ethernet connections.
  4. A crossover is used to connect two Ethernet devices without a hub or for connecting two hubs.
  5. A crossover has one end with the Orange set of wires switched with the Green set.
  6. Odd numbered pins are always striped, even numbered pins are always solid colored.
  7. 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.
  8. No more than 1/2″ of the Ethernet cable should be untwisted otherwise it will be susceptible to crosstalk.
  9. 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.

————————– Thanks everyone


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1 Comment

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    sorfuddin ahmad on

    Really your post is little bit different bcz when a fresh learner, learn about this topics definitely he/she can understand easily what is RJ45,UTP,STP etc. so thanks & stay fine.

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