ANSI/TIA 568 C.2

Balanced Twisted–Pair Telecommunications Cabling and Components Standard

The ANSI/TIA 568 C.2 standard is written by the Telecommunications Industry Association and is meant to eliminate misunderstandings between manufacturers and purchasers, facilitate interchangeability and product improvement and to help a purchaser select the proper product for their needs. This standards document specifically covers 100Ω Category 3, Category 5e, Category 6 and Category 6A twisted–pair cabling and components. The document specifies both mandatory and advisory criteria. The mandatory criteria specify the minimum acceptable requirements that apply to protection, performance, administration and compatibility. The advisory criteria present criteria that will enhance the performance of the cabling system. The document is divided into the following three main sections:

General

The general section specifies the backward compatibility and interoperability of the cabling. This means that all newer versions cables must meet the requirements of, support the transmissions of and operate in a system with older versions of cable. It is important to note that when older cables or equipment are used in a system with newer cables the performance will be limited to the slowest system component. The general section also specifies the recognized cable categories and their transmission characteristics.

Cable Category	Category 3	Category 5e	Category 6	Category 6a
Cable Type	100Ω balanced twisted–pair	100Ω balanced twisted–pair	100Ω balanced twisted–pair	100Ω balanced twisted–pair
Transmission Characteristic	1 to 16 MHz	1 to 100 MHz	1 to 250 MHz	1 to 500 MHz

This standard no longer recognized the older legacy cabling standards of Category 1, 2, 4 and 5.

Mechanical Requirements

This portion of the document defines the physical characteristics and mechanical performance specifications the cable must meet. This section also defines that the performance can only be achieved with the use of compliant components. Each category of cable must consist of four twisted pairs with solid or stranded conductors sized between 22AWG and 24AWG with thermoplastic insulation and an overall thermoplastic jacket with a diameter less than or equal to 9.0mm. This section also states that the cables must meet the mechanical performance requirements, testing and test methods defined below:

Category 3 — ANSI/CEA S–90–661–2006
Category 5e — ANSI/CEA S–90–661–2006
Category 6 — ANSI/CEA S–102–732–2009
Category 6A — ANSI/CEA S–102–732–2009

This portion of the standard also defines the internal color code of the conductors in the cable.

Pair 1 — White–Blue, Blue
Pair 2 — White–Orange, Orange
Pair 3 — White–Green, Green
Pair 4 — White–Brown, Brown

Additionally, this portion of the standard provides the two standard pinouts, T568A and T568B, for the use of this cable type with eight position modular connectors.

T568A	T568B
Pin — Conductor Color	Pin — Conductor Color
1 — White–Green	1 — White–Orange
2 — Green	2 — Orange
3 — White–Orange	3 — White–Green
4 — Blue	4 — Blue
5 — White–Blue	5 — White–Blue
6 — Orange	6 — Green
7 — White–Brown	7 — White–Brown
8 — Brown	8 — Brown

Note: T568B is the more commonly used.

Transmission Requirements

This section covers the performance specifications of the cable and components.

Return Loss: The loss of signal power as a result of signal reflection at a discontinuity in the cable.
Insertion Loss: The loss of signal power that results from devices inline.
Near End Crosstalk Loss (NEXT): Loss caused by interference between two pairs in the cable, measured at the same end of the cable as the transmitter.
Power Sum Near End Crosstalk Loss (PSNEXT): Loss caused by the sum of near–end crosstalk of three pairs in the cable as they affect the fourth.
Far End Crosstalk Loss (FEXT): Loss caused by interference between two pairs in the cable, measured at the opposite end of the cable from the transmitter.
Attenuation Crosstalk Ratio Far End (ACRF): The difference between the signal attenuation and the far–end crosstalk, measured in decibels.
Power Sum Attenuation Crosstalk Ration Far End (PSACRF): The difference between the signal attenuation and the power sum far–end crosstalk, measured in decibels.
Transverse Conversion Loss (TCL): The ratio of the measured common mode voltage on a pair relative to a differential mode voltage applied on that same pair.
Equal Level Transverse Conversion Transfer Loss (ELTCTL): The ratio of the measured common mode voltage on a pair relative to a differential mode voltage on a different pair and normalized to be independent of length.
Coupling Attenuation: The ratio between the wanted signal power and the unwanted radiated power from the cabling.
Propagation Delay: The amount of time it takes for a signal to travel from the transmitter to the receiver over the cable.
Propagation Delay Skew: The difference in propagation delay between the fastest pair and the slowest pair.
Power Sum Alien Near–End Crosstalk Loss (PSANEXT): Loss on one pair caused by the sum of alien crosstalk from other cables measured at the same end of the cable as the transmitter.
Average Power Sum Alien Near End Crosstalk Loss (Average PSANEXT): Average loss on all pairs caused by the sum of alien crosstalk from other cables measured at the same end of the cable as the transmitter.
Power Sum Alien Far–End Crosstalk Loss (PSAFEXT): Loss on one pair caused by the sum of alien crosstalk from other cables measured at the opposite end of the cable from the transmitter.
Power Sum Alien Attenuation to Crosstalk Ratio Far–End (PSAACRF): The difference between the signal attenuation and the power sum alien far–end crosstalk, measured in decibels.

This white paper is for informational purposes only and is subject to change without notice. C2G makes no guarantees, either expressed or implied, concerning the accuracy, completeness or reliability of the information found in this document.