T568A vs T568B: Ethernet Cable Wiring Standards Explained

This article compares T568A and T568B wiring standards and highlights the differences between their wiring diagrams. Both standards are commonly used with 10/100BaseT cables. We’ll delve into crossover and straight-through cable configurations, examining their wiring connections in detail. These standards work with eight-conductor balanced twisted-pair cables, like Category 5, and 8P8C modular connectors (such as RJ45 connectors) with a 100-ohm impedance.

Let’s explore each standard:

T568A Wiring Diagram

T568A is a standard for Ethernet wiring. The image above illustrates the T568A jack pinouts.

T568B Wiring Diagram

T568B, also a standard for Ethernet wiring, has a slightly different pinout configuration. The figure above shows the T568B jack pinouts.

Crossover Cable Wiring Connections

Crossover cables are wired with a T568A male connector on one end and a T568B male connector on the other. This configuration allows direct communication between two devices of the same type (e.g., PC to PC or switch to switch). The table below details the wiring:

Table 1: Crossover Cable Wiring

Straight Through Cable Wiring Connections

Straight-through cables have the same wiring standard (either T568A or T568B) on both ends. These cables are typically used to connect PCs and other end-user devices to network devices like hubs and switches.

Table 2: Straight Through Cable Wiring