Ethernet 10/100/1000Base-T and 100Base-T4 Crossover
From HwB
Also known as Crossed Network cable
This cable can be used to cascade hubs, or for connecting two Ethernet stations back-to-back without a hub. It works with 10Base-T, 100Base-TX, 100Base-T4 and 1000Base-T. Use a good enough cable, if you are confused about categories of cables then use category 5e(nhanced) and you'll be fine even at 1000Base-T.
Pinout
RJ45 MALE CONNECTOR to network interface card 1.
RJ45 MALE CONNECTOR to network interface card 2.
(1000Base-T names in parentheses)
| Name | NIC1 | Color | NIC2 | Name |
|---|---|---|---|---|
| TX+ (BI_DA+) | 1 | White/Orange | 3 | RX+ (BI_DB+) |
| TX- (BI_DA-) | 2 | Orange | 6 | RX- (BI_DB-) |
| RX+ (BI_DB+) | 3 | White/Green | 1 | TX+ (BI_DA+) |
| - (BI_DC+) | 4 | Blue | 7 | - (BI_DD+) |
| - (BI_DC-) | 5 | White/Blue | 8 | - (BI_DD-) |
| RX- (BI_DB-) | 6 | Green | 2 | TX- (BI_DA-) |
| - (BI_DD+) | 7 | White/Brown | 4 | - (BI_DC+) |
| - (BI_DD-) | 8 | Brown | 5 | - (BI_DC-) |
That means that the white/orange cable connected to NIC 1 pin 1 should go to NIC 2 pin 3 and NIC 1 pin 2 to NIC 2 pin 6 etc.
Notes:
- It's important that each pair is kept as a pair. TX+ & TX- must be in the pair, and RX+ & RX- must together in another pair. (Just as the table above shows).
- While 10Base-T and 100Base-TX only uses 2 pairs, please connect all four since 100Base-T4 and 1000Base-T needs them and save yourself some future debugging :)
- The colors originate from the numbering and name on NIC1.
Contributions
- Joakim Ögren
- Niklas Edmundsson
- Jim C?
- Jason D. Pero
- Oscar Fernandez Sierra
- Cayce Balara
- Jeffrey R. Broido
- Patrick Smart
- Jeffrey R. Broido
- Kim Scholte
Sources
- IEEE Std 802.3, 2000 Edition