Network Cabling Information

Making network cable is easy, as long as you have the right tools (Cable, Crimper, and RJ45 ends)..


  1. Spread and arrange the pairs roughly in the order of the desired cable end.
  2. Untwist the pairs and arrange the wires in the order of the desired cable end. Flatten the end between your thumb and forefinger. Trim the ends of the wires so they are even with one another. It is very important that the unstripped (untwisted) end be slightly less than 1/2″ long. If it is longer than 1/2″ it will be out-of-spec and susceptible to crosstalk. If it less than slightly less than 1/2″ it will not be properly clinched when RJ-45 plug is crimped on.. Flatten again. There should be little or no space between the wires.
  3. Hold the RJ-45 plug with the clip facing down or away from you. Push the wire firmly into the plug. Now, inspect the darn thing… before crimping and wasting the plug! Looking through the bottom of the plug, does it match the wiring diagram that your using?
  4. Hold the wire near the RJ-45 plug with the clip down and firmly push it into the left side of the front of the crimper (it will only go in one way). Hold the wire in place squeeze the crimper handles quite firmly.
  5. Test the crimp… If done properly an average person will not be able to pull the plug off the cable with his or her bare hands. And that quite simply, besides lower cost, is the primary advantage of twisted-pair cables over the older thinwire, coaxial cables. In fact, I would say the RJ-45 and ease of its installation is the main reason coaxial cable is no longer widely used for small Ethernets. But, don’t pull that hard on the plug. It could stretch the cable and change its characteristics. Look at the side of the plug and see if it looks like the diagram and give it a fairly firm tug to make sure it is crimped well.
  6. If both ends of the cable are within reach, hold them next to each other and with RJ-45 clips facing away. Look through the bottom of the plugs. If the plugs are wired correctly, and they are identical, it is a straight-thru cable. If they are wired correctly and they are different, it is a crossover cable.

Here’s some recommendation for when you are running your Ethernet cables…

  • Cat 5, 5e, 6, 6a Cable lengths are limited to 100 Meters (roughly 328 Ft).  Try not to exceed 300 Ft.  If you need have a cable run that is longer, consider a powered ethernet repeater.
  • Category 5E is the *recommended* minimum.
  • Try to avoid running cables parallel to power cables.
  • Do not bend cables to less than four times the diameter of the cable.
  • If you bundle a group of cables together with cable ties (zip ties), do not over-cinch them. It’s okay to snug them together firmly; but don’t tighten them so much that you deform the cables.
  • Keep cables away from devices which can introduce noise into them. Here’s a short list:
    • copy machines
    • electric heaters
    • speakers
    • printers
    • TV sets
    • fluorescent lights
    • copiers
    • welding machines
    • microwave ovens
    • telephones
    • fans
    • elevators
    • motors
    • electric ovens
    • dryers
    • washing machines
    • shop equipment
  • Avoid stretching UTP cables (tension when pulling cables should not exceed 25 LBS).
  • Do not run UTP cable outside of a building. It presents a very dangerous lightning hazard!
  • Do not use a stapler to secure UTP cables. Use telephone wire/RG-6 coaxial wire hangers which are available at most hardware stores.

For 110 blocks, check out the 110 Punchdown Wiring Guide from Cables to Go.