RJ-45 Pinouts and Category 5 Wiring
You should apperceive the capacity of cross-over and straight-through Category 5 (Cat 5) or Cat 5e
cabling for best any networking job. The EIA/TIA defines the cabling blueprint for Ethernet
LANs (http://www.eia.org and http://www.tiaonline.org), including the pinouts for the RJ-45
connects, as apparent in Figure 1-1.
Figure 1-1 RJ-45 Pinouts with Four-Pair UTP Cabling
The best accepted Ethernet standards (10BASE-T and 100BASE-TX) anniversary use two askance pairs
(specifically pairs 2 and 3 apparent in Figure 1-1), with one brace acclimated for manual in each
direction. Depending on which brace a accessory uses to address and receive, either a straight-through
or cross-over cable is required. Table 1-2 summarizes how the cabling and pinouts work.