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 other 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-directional Data Two Plus |
| (BI_D1+) | (BI_D2+) |
2 | Bi-directional Data One Minus | Bi-directional Data Two Minus |
| (BI_D1-) | (BI_D2-) |
3 | Bi-directional Data Two Plus | Bi-directional Data One Plus |
| (BI_D2+) | (BI_D1+) |
4 | Bi-directional Data Three Plus | Bi-directional Data Four Plus |
| (BI_D3+) | (BI_D4+) |
5 | Bi-directional Data Three Minus | Bi-directional Data Four Minus |
| (BI_D3-) | (BI_D4-) |
6 | Bi-directional Data Two Minus | Bi-directional Data One Minus |
| (BI_D2-) | (BI_D1-) |
7 | Bi-directional Data One Plus | Bi-directional Data One Plus |
| (BI_D4+) | (BI_D3+) |
8 | Bi-directional Data Four Minus | Bi-directional Data Three Minus |
| (BI_D4-) | (BI_D3-) |
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