How to Make a Cat 5 Pass-Through

By John PlatePosted on

There are two main types of Category (cat) 5 Ethernet cables, and two different wiring standards. This article shows you how to create a pass-through (also called straight-through) Ethernet cable using either of the two primary standards.

How to Make a Cat 5 Pass-Through

Things You’ll Need

Category 5 Unshielded Twisted Pair (UTP) Page 2 8 8 Pin Contact ( 8P8C ) Plug
Compression Tool Connectors
Wire Stripper / Cutter

How to Make a Cat 5 Pass-Through

Assemble Your Materials

  1. Acquire a compression tool. All of these materials are likely to be available at a good hardware store, or a place that specializes in do-it-yourself materials, such as Radio Shack. Crimps can be unique to a single connector, but are often made to crimp more than one type of connector. The crimp tool shown in the photograph will crimp the four and eight connector plugs. This is an advantage if you also plan to make calls to conventional phone lines.
  2. Purchase your cable. Unshielded twisted-pair Ethernet standards cable service by at least three categories (cat 3) cable, but cat 3 will not support the data transmission rates people are using even at home. Category five ( Cat 5 ) UTP supports data rates as high as 100 megabits per second, which are now common in low-cost hubs, switches, and home computers. Cat 6 cable supports up to gigabit data rates, but these are still not common in the home.
  3. Purchase your connectors. Although often called RJ-45 connectors, the official term is an eight-pin, eight-connector connection. It is commonly abbreviated 8P8C. They will likely be sold in a pack, but they are not expensive. Having more than you might initially need is also a good idea because it’s possible to mess up the work and have to try again.
  4. Choose a pattern. There are two competing standards for terminating wires in Cat 5 Ethernet: T568A and T568B. The difference is in the string of threads. If you plan to use this cable in a high-performance environment, research the standard used by hub and screen patch providers and use the same standard. For most uses, patterns are not important to understand. T568B is referenced by Cisco Systems documentation, so the wiring standard used in Section 2.
  5. Plan your routes. The Unshielded part of UTP is important when planning your cable length. Because the cable does not have any shielding, it may be susceptible to interference from other devices. The classic hazard discussed in the literature is the fluorescent luminaire. These generate electromagnetic interference and should be avoided. If it runs on electricity or carries electricity, try to avoid it or at least cross it at a right angle.UTP Ethernet specifications call for cable lengths of no more than 100 meters. This means that if you plan to run this Ethernet the length of your house (and it’s a big house), you may need to break the trip into segments and use a small, powered hub to do the work from a distance.

Crafting cable

  1. Practice first. There’s nothing worse than having everything lined up perfectly and then having to do it all over again because something went wrong. While it’s not complicated, tightening the 8P8C connectors at the end of the cable is a skill and can be done incorrectly. Because the cable is sold in spools, and connectors by the dozen, there is little reason not to simply cut a length for practice. Try making four different lengths before making a cable you really want to keep.
  2. Cut the cable to size. Especially if your cord is stretching through the house, leave a little more than you need, just in case you need to nail the final a second time. Using pliers, cut the end into a sharp grip. Do not twist or pull the cable. Squeeze cleanly through all layers in a scissors-like motion.
  3. Expose the individual wires. Cat 5 UTP has an outer jacket that wraps around four pairs of wires, each with its own insulation. Carefully peel the outer coat away from the pairs and leave about an inch of these pairs bare. Fan these non-standard pairs you need for your cabling pattern and resize them to be exactly the same length.
  4. Add the plug. The 8P8C connector has small channels to guide each individual wire in the cable out to the end of the plug. The crimp tool will drive the contacts through the individual wire insulation, so there is no need to strip each wire in the jacket. Just lighten them up at the outlet, ensuring they remain separate and in the necessary order from your cabling pattern.
  5. Twice check the fit. A common problem with this process is that wires that don’t quite make it all the way to the end of the plug connector, or wires, that are exposed between the end of the plug and the beginning of the cable jacket. Since the only way to fix a plug after the crimp is to cut it and add another one, this is the time to ensure things look good.
  6. Crimp the end. This is the fun part, but also the part where things potentially unravel. Carefully slide the plug and its cable into the crimp tool and without letting this shift around, squeeze the crimp tool as if you were cutting the connector. You will repeat these steps in exactly the same way for the other end of the cable to make a straight-through Ethernet cable.