TheBSGTT | C4 - 568A and 568B

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Friday, September 03, 2010

The Bright Spark's Guide to Telecommunications

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TheBSGTT

C4 - 568A and 568B

TheBSGTT

Here are a couple of graphics on the C4 punch-down.

Where do you find C4's?
Station Jacks	These come in different shapes and forms but most contain at least two C4's. Voice on the top or left insert module. Data on the bottom or right insert module.
110 RJ45 Patch Panels	If you get a chance - check out the back of the Data Patch Panel. You should see C4's up the ying-yang. Terminated C4's can either look like a work-of-art or a cluster-you-know-what. Termination work requires a lot of skill & patience.
110 Telephony Patch Panel - Station side	The wrinkle here is that the 8 conductor cables are terminated below the C4. The top Blue/Orange/Green/Brown are used to jumper or cross-connect voice, modem and fax. Herein lies the art of the punch-down both for voice and data: Make sure you are straight on the vertical and horizontal. Punch the connection only once if possible (make sure your blades are in good shape.) If you're careless and have to do it several times - guess what - you probably will have to pull the C4 off to replace it! Ask any technician and they will tell you - it ain't easy to do and it eats you alive - time wise. So a little patience and care can mean the difference between working from 08:00 to 17:00 or 08:00 to Midnight. Of course, you can return a couple of days later to fix everything because your terminations did not pass the certification standards or worse still - 100 new phone lines don't have dial-tone! Ever heard of unemployment????

A few notes....

Color-Coding:

It's pretty difficult to draw broken white/blue - blue/white lines and so on. Suffice to say - I have taken it for granted that you have at least held a stripped-back twisted-pair Category Five Cable in your hand.

Some Category 5 specs:

AWG 24* (American Wire Gauge) - the lower the number - the larger the gauge.

Maximum bend radius on multi-cable Backbone run = 10 times the diameter of the total Cable Backbone cables.
>Maximum bend radius on single-cable run = 4 times the diameter of the single cable.
>Maximum un-twist (each pair) to terminate punch-down - 1/2 inch.

Transmission Performance:

100 MHz

Supported Distance:

90 meters (295 feet) on the horizontal.
Jumper or Patch cables should not exceed 10 meters (33 feet).
Station cables should not exceed 5 meters (16 feet).