Tuesday, September 11, 2012

Difference Between CAT5 and CAT6 Cable And Connector


Yes, there is a difference. Cat6 uses thicker copper and insulation which helps in reducing near end cross talk - the CAT6 jacks are made to take this into account (the terminations are staggered on a Cat6 jack, but in a straight line on Cat5E).

Some category 6 cable designs have a spline to increase the separation between pairs and also to maintain the pair geometry. This additional separation improves NEXT performance and allows category 6 compliance to be achieved. With advances in technology, manufacturers have found other ways of meeting category 6 requirements. The bottom line is the internal construction of the cable does not matter, so long as it meets all the transmission and physical requirements of category 6. The standard does not dictate any particular method of cable construction.


The trends of the past and the predictions for the future indicate that data rates have been doubling every 18 months.

To install the wiring use velcro straps (instead of cable tie). Also, keep it at least 300 mm away from power cables and when you tie it up don't do it too tight. Terminations need to maintain the pair twist as close to the back of the socket as possible.

The general difference between category 5e and category 6 is in the transmission performance, and extension of the available bandwidth from 100 MHz for category 5e to 250 MHz for category 6. This includes better insertion loss, near end crosstalk (NEXT), return loss, and equal level far end crosstalk (ELFEXT). These improvements provide a higher signal-to-noise ratio, allowing higher reliability for current applications and higher data rates for future applications.

A simple open wire circuit consisting of two wires is considered to be a uniform, balanced transmission line. A uniform transmission line is one which has substantially identical electrical properties throughout its length, while a balanced transmission line is one whose two conductors are electrically alike and symmetrical with respect to ground and other nearby conductors.* "Electrically balanced" relates to the physical geometry and the dielectric properties of a twisted pair of conductors. If two insulated conductors are physically identical to one another in diameter, concentricity, dielectric material and are uniformly twisted with equal length of conductor, then the pair is electrically balanced with respect to its surroundings. The degree of electrical balance depends on the design and manufacturing process. Category 6 cable requires a greater degree of precision in the manufacturing process. Likewise, a category 6 connector requires a more balanced circuit design. For balanced transmission, an equal voltage of opposite polarity is applied on each conductor of a pair. The electromagnetic fields created by one conductor cancel out the electromagnetic fields created by its "balanced" companion conductor, leading to very little radiation from the balanced twisted pair transmission line. The same concept applies to external noise that is induced on each conductor of a twisted pair. A noise signal from an external source, such as radiation from a radio transmitter antenna generates an equal voltage of the same polarity, or "common mode voltage," on each conductor of a pair. The difference in voltage between conductors of a pair from this radiated signal, the "differential voltage," is effectively zero. Since the desired signal on the pair is the differential signal, the interference does not affect balanced transmission. The degree of electrical balance is determined by measuring the "differential voltage" and comparing it to the "common mode voltage" expressed in decibels (dB). This measurement is called Longitudinal Conversion Loss "LCL" in the Category 6 standard. * The ABC’s of the telephone Vol. 7
Category 5e requirements are specified up to 100 MHz. The category 6 standard sets minimum requirements up to 250 MHz (Class E) for cables, connecting hardware, patch cords, channels and permanent links, and therefore guarantees reasonable performance that can be utilized by applications.

From a future proofing perspective, it is always better to install the best cabling available. This is because it is so difficult to replace cabling inside walls, in ducts under floors and other difficult places to access. The rationale is that cabling will last at least 10 years and will support at least four to five generations of equipment during that time.




Although Category 6 and Category 5e connectors may look alike, Category 6 connectors have much better transmission performance. For example, at 100 MHz, NEXT of a Category 5e connector is 43 decibels (d, while NEXT of a Category 6 connector is 54 dB. This means that a Category 6 connector couples about 1/12 of the power that a Category 5e connector couples from one pair to another pair. Conversely, one can say that a Category 6 connector is 12 times less "noisy" compared to a Category 5e connector.

Because of its improved transmission performance and superior immunity from external noise, systems operating over category 6 cabling will have fewer errors vs. category 5e for current applications. This means fewer re-transmissions of lost or corrupted data packets under certain conditions, which translates into higher reliability for category 6 networks compared to category 5e networks.

It's always best to match the same brand cat5e or 6 cable with the same brand/class Jack. They are designed to be tuned together and give best performance.

Cat6 is certified (this might change) to run 10gig over 55m.

Reference
Broadband Utopia
Tech Support Forum
CAT 5 Cable Company.com

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