Wiring Standards

T568A and T568B wiring: what's the difference, and how do I know which one to use?
T568A and T568B are the two wiring standards for an 8-position modular connector, permitted under the TIA/EIA-568-A wiring standards document. The only difference between T568A and T568B (also known as Weco, AT&T 258A) is that the orange and green wire pairs (pairs two and three) are interchanged.

T568A wiring T568B wiring

Standard 4-Pair Wiring Color Codes
Pair 1
Pair 1 T White/Blue
R Blue/White
Pair 2
Pair 2 T White/Orange
R Orange/White
Pair 3
Pair 3 T White/Green
R Green/White
Pair 4
Pair 4 T White/Brown
R Brown/White
Note: For 6-wire jacks use pair 1, 2 and 3 color codes.
For 4-wire jacks, use Pair 1 and 2 color codes.

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How to decide which wiring pattern to use:

  1. Does the job specification call out a wiring pattern?
  2. Does the customer/end user have a preference for T568A or T568B?
  3. Have patch panels already been purchased for the job? If so, they will probably be either T568A or T568B. The jacks should be wired to the same pattern as the panels.
  4. Are you adding on to an existing wiring plan? If so, your new wiring should match the existing wiring.

If none of the factors above apply, either T568A or T568B may be used. It is important to ensure that the workstation connectors and the patch panels are wired to the same pattern. T568B is commonly used in commercial installations, while T568A is prevalent in residential installations.

SignamaxCategory 5e+ Component Level Patch Cords

Category 5e+ Component Level Patch CordsCategory 5e+ Patch Cords provide an increased level of performance above our standard Category 5e patch cords. These cords accommodate both T568A and T568B wiring applications, and are offered in a variety of popular colors for easy circuit identification. These premium cords exceed component level performance for patch cords as specified in TIA/EIA-568-B.2.

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Category 5e+ Component Level Patch Cords

SignamaxCat-5e Patch Panels

Cat-5e Patch PanelsCategory 5e+ patch panels are designed to exceed TIA/EIA-568-B.2 component, permanent link and channel level performance specifications providing usable bandwidth beyond 155 MHz. These high-density panels are available in 12 through 96 port versions and feature enhanced front and rear labeling features for easy circuit identification. Category 5e+ panels support both T568A and T568B wiring configurations using an easy to read color-coded wiring label.

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Cat-5e Patch Panels

Leviton Network & Telephone Inserts

Network and Telephone InsertsLeviton's snap-in connectors feature dual color coded wiring labels with both T568A and T568B wiring patterns, for dual flexibility in a single connector, plus fast, accurate termination of station wiring.

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Network & Telephone Inserts