Twisted-Pair Cable and Pin Assignments

B-3

B
You must connect all four wire pairs as shown in the following diagram to support
Gigabit Ethernet.
Figure B-3 Crossover Wiring
1000BASE-T Pin Assignments
All 1000BASE-T ports support automatic MDI/MDI-X operation, so you can use
straight-through cables for all network connections to PCs or servers, or to othe r
switches or hubs.
The table below shows the 1000BASE-T MDI and MDI-X port pinouts. These ports
require that all four pairs of wires be connected. Note that for 1000BASE-T
operation, all four pairs of wires are used for both transmit and receive.
Use 100-ohm Category 5, 5e or 6 unshielded twisted-pair (UTP) or shielded
twisted-pair (STP) cable for 1000BASE-T connections. Also be sure
that the length
of any twisted-pair connection does not exceed 100 meters (328 feet )
.
Table B-2 1000BASE-T MDI and MDI-X Port Pinouts
Pin MDI Signal Name MDI-X Signal Name
1 Bi-directional Data One Plus (BI_ D1+) Bi-directional Data Two Plus (BI_D2+)
2 Bi-directional Data One Minus (BI_D1-) Bi-directional Data Two Minus (BI_D2-)
3 Bi-directional Data Two Plus (BI_D2+) Bi-directio nal Data One Plus (BI_D1+)
4 Bi-directional Data Three Plus (BI_D3+) Bi-directional Data Four Plus (BI_D 4+)
5 Bi-directional Data Three Min us (BI_D3-) Bi-directional Data Four Minus (BI_D4-)
6 Bi-directional Data Two Minus (BI_D2-) Bi-directional Data One Minus (BI_D1-)
7 Bi-directional Data Four Plus (BI_D4+) Bi-directional Data Three Plus (BI_D3+)
8 Bi-directional Data Four Minus (BI_D4-) Bi-directional Data Three Minus (BI_D3-)
White/OrangeStripe
Orange
White/GreenStripe
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
EIA/TIA568B RJ-45 Wiring Standard
10/100BASE-TXCrossover Cable
EndAEnd B
Green
Blue
White/BlueStripe
Brown
White/BrownStripe