VDV Works Virtual Hands-On Training


Cat 3 and Cat 5/5E/6 UTP Termination

Cat 5/5E/6 Jacks


Step 1 NEXT BACK  Terminating Cat 5/5E/6 Jacks

You will need:

Cat 5 cable

Cat 5 jack

110 punchdown tool

Hand held termination aid, if available


 Lesson Plan Links

Home Page

Cat 5 - 110 Punchdown Block

Cat 5 - Jack

Cat 3 - 66 Punchdown Block

Cat 3 - Jack

Cat 3 & Cat 5 - Plug

Go to the quiz


You will need to terminate jacks for small patch panels (1) and work area outlets (4).

If you are installing Cat 5, make sure the jack you are terminating is a Cat 5 jack. There are Cat 3 jacks as well, and they have a similar appearance, but will degrade the performance of Cat 5 cable to Cat 3 levels if used in a Cat 5 link!


 Cat 5 Jacks generally have 110 - style punchdown IDC connections for the wires, so they are terminated similarly to 110 blocks.

Cat 5 jacks will be wired either T568A or T568B, with the only difference being the reversal of pairs 2 and 3 - a matter of convention that confuses many novices (and a few experts too!)

However, do not even think of memorizing the pin color code - Cat 5 jacks have internal "twists" to maintain NEXT performance, so the color code is unique to the Cat 5 jack.

Simply follow the color codes on the jack to get the pinout correct!

Cat 3 Jacks have as many as four wiring configurations, usually detailed on the package. They only apply to Cat 3 jacks, since they do not have internal "twists" to confuse you!

Begin the process by stripping the jacket from the cable, but, for jack termination, you should only expose 1-1/2 inches (37 mm) of the twisted wires. Untwist the wires to about 1/2 inch from the end of the jacket.

Like for the 110 block, untwist the pairs for placing in the slots of the jack.

At this point it is important to realize that separating the wires does not follow the same BL-O-G convention as a punchdown. The pairs are split up at the jack to minimize crosstalk.

There are 2 wiring configurations that you can use: they are referred to as 568A and 568B. The patterns are illustrated on the body of the Cat 5 jack itself.



Slide the jack into the hand held termination aid and hold it as shown. This will provide a steady platform for holding the jack, lining up the wires into the punchdown slots and punching the wires down. The 568A and B wiring patterns will be clearly visible above the punchdown slots.


Notice the two color codes on this Cat 5 jack, one for T568A and one for T568B - don't get confused!


Now lay the wires in the slots according to the termination type you will use (T568A or T568B.) Follow the color code on the jack exactly. Keep the twists as close to the jack as possible to minimize crosstalk!

 Some manufacturers make jacks that can be terminated without a punchdown. They use the plastic cap on the back to push the wires into the IDC contacts - usually with a pair of pliers to insure the full insertion. If you use this technique, remember to cut the wires to the proper length and still maintain your twists close to the jack.


Once the wires are in place, use the punchdown tool to make the connection and cut off the excess wire.


Snap the plastic cover on the back of the jack and it's complete.



You can now insert the completed jack into the work area outlet box or patch panel.




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