Standard, Straight-Through Wiring (both ends are the same):
RJ45 Pin # | Wire Color | Wire Diagram | 10Base-T Signal | 1000Base-T Signal |
1 | White/Green |  | Transmit+ | BI_DA+ |
2 | Green |  | Transmit- | BI_DA- |
3 | White/Orange |  | Receive+ | BI_DB+ |
4 | Blue |  | Unused | BI_DC+ |
5 | White/Blue |  | Unused | BI_DC- |
6 | Orange |  | Receive- | BI_DB- |
7 | White/Brown |  | Unused | BI_DD+ |
8 | Brown |  | Unused | BI_DD- |
Straight-Through Cable Pin Out for T568A
RJ45 Pin # | Wire Color | Wire Diagram | 10Base-T Signal | 1000Base-T Signal |
1 | White/Orange | | Transmit+ | BI_DA+ |
2 | Orange | | Transmit- | BI_DA- |
3 | White/Green | | Receive+ | BI_DB+ |
4 | Blue | | Unused | BI_DC+ |
5 | White/Blue | | Unused | BI_DC- |
6 | Green | | Receive- | BI_DB- |
7 | White/Brown | | Unused | BI_DD+ |
8 | Brown | | Unused | BI_DD- |
Straight-Through Cable Pin Out for T568B
Pair 1 (T1 & R1)
Usually the primary dial tone or talk circuit is wired to the center two pins (pins 3 & 4) and is the white/blue and blue/white pair (AKA: T1 & R1 – tip 1 and ring 1). A standard single line phone draws dial tone from these center pins.
NOTE: The type of wiring shown here is known as USOC (pronounced U-sock). See background below.
The multi-conductor cables attached to RJ11 connectors usually have colored sheaths.
position | RJ25 pin | RJ14 pin | RJ11 pin | Pair | T/R | ± | Cat 5e/6 colors | Colors | Old colors |
1 | 1 | 3 | T | + | white/green | white/green | white | ||
2 | 2 | 1 | 2 | T | + | white/orange | white/orange | black | |
3 | 3 | 2 | 1 | 1 | R | – | blue | blue/white | red |
4 | 4 | 3 | 2 | 1 | T | + | white/blue | white/blue | green |
5 | 5 | 4 | 2 | R | – | orange | orange/white | yellow | |
6 | 6 | 3 | R | – | green | green/white | blue |