1000BASE-T (also known as IEEE 802.3ab) is a standard for Gigabit Ethernet over copper wiring (RJ45 connection). It requires, at least Category 5 cable (the same as 100BASE-TX), but Category 5e (Category 5 enhanced) or Category 6 cable may also be used and are often recommended. 1000BASE-T requires all four pairs to be present and is far less tolerant of poorly installed wiring than 100BASE-TX.
| Pin | Name | Description |
|---|---|---|
| 1 | BI_DA+ | Bi-directional pair A + |
| 2 | BI_DA- | Bi-directional pair A - |
| 3 | BI_DB+ | Bi-directional pair B + |
| 4 | BI_DC+ | Bi-directional pair C + |
| 5 | BI_DC- | Bi-directional pair C - |
| 6 | BI_DB- | Bi-directional pair B - |
| 7 | BI_DD+ | Bi-directional pair D + |
| 8 | BI_DD- | Bi-directional pair D - |
Each network segment cable length may be up to 100 meters, although several chip manufacturers claim 150 meters. Autonegotiation is a requirement for using 1000BASE-T, according to the standard. Several device drivers will allow you to force 1000 Mbps full duplex to eliminate autonegotiation issues. If pins 4,5,7 & 8 are not connected or punched properly the speed falls back to 100 mbps.
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