SIGNALTEK Operation Manual 1-5
10/100 Ethernet requires two twisted pairs to be terminated to the
RJ-45 connector. Each transceiver will transmit on pins 1/2 and
receive on pins 3/6.
Figure 1-1 T-568 A/B Color Code
There is no performance difference between T568-A and T568-B
wiring configurations. However most standards recommend the
use of the T568-A configuration since it provides better
compatibility with telephone wiring used in residential applications.
Gigabit Ethernet (1000Base-T) operates over Category 5 or better
cable and utilizes all four pairs of the cable.
Table 1-1 Ethernet Signaling
RJ-45 Pin # 10/100 Mbps 1000Mbps
1 Tx + Bi-Dir A +
2 Tx - Bi-Dir A -
3 Rx + Bi-Dir B +
4 Unused Bi-Dir C +
5 Unused Bi-Dir C -
6 Rx - Bi-Dir B -
7 Unused Bi-Dir D +
8 Unused Bi-Dir D -