ISDN BRI provides 2B+D channels (2×64 kbps + 16 kbps = 128 kbps usable) over a standard RJ45 connector. Legacy internet and ISDN phone line interface.
| Pin | Name | Function | Type |
|---|---|---|---|
| 3 | TX+ | Transmit positive to NT | BUS |
| 4 | RX+ | Receive positive from NT | BUS |
| 5 | RX- | Receive negative from NT | BUS |
| 6 | TX- | Transmit negative to NT | BUS |