100BASE-T4 is an early implementation of Fast Ethernet.
| Pin | Name | Description |
|---|---|---|
| 1 | TX_D1+ | Transmit Data+ |
| 2 | TX_D1- | Transmit Data- |
| 3 | RX_D2+ | Receive Data+ |
| 4 | BI_D3+ | Bi-directional Data+ |
| 5 | BI_D3- | Bi-directional Data- |
| 6 | RX_D2- | Receive Data- |
| 7 | BI_D4+ | Bi-directional Data+ |
| 8 | BI_D4- | Bi-directional Data- |
One pair is reserved for transmit, one for receive, and the remaining two will switch direction as negotiated.
Note: TX & RX are swapped on Hub´s. Don´t know about Bi-directional data


