T568A & T568B Wiring Scheme

T568A & T568B Wiring Scheme
T568 A or T568 B - Which One Should You Choose?

The primary reason for T568A wiring is to accomodate a voice telephone line should an RJ11 connector get plugged into an RJ45 jack

If the installation is residential, choose T568A unless other conditions apply (see below).
If there is pre-existing voice/data wiring (remodel, moves, adds, changes), duplicate this wiring scheme on any new connection.
If project specifications are available, use the specified wiring configuration.
If components used within the project are internally wired either T568A or T568B, duplicate this wiring scheme.

Leviton Integrated Networks uses T568A in all of its circuit boards.

Standards

• ANSI/TIA/EIA-568-B " Commercial Building Telecommunications Cabling Standard" lists both wiring configurations.
• T568B is the most prevalent for commercial installations.
• ANSI/TIA/EIA-570-B " Residential Telecommunications Cabling Standards" recommends T568A