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.
(To network interface card 1).
(To network interface card 2).
RJ45 MALE CONNECTOR to network interface card 1.
RJ45 MALE CONNECTOR to network interface card 2.
(1000Base-T names in parentheses)
|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.
Note 1: 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).
Note 2: 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 :)
Note 3: The colors originate from the numbering and name on NIC1.
Note 4: The pinout of this cable differs from what people usually calls a crossover cable since all pairs are swapped. If you need a crossover cable for use with special applications like serial cables you should not cross the pairs 4/5 and 7/8.
|Contributor:||Joakim Ögren, Niklas Edmundsson, Jim C?, Jason D. Pero, Oscar Fernandez Sierra, Cayce Balara, Jeffrey R. Broido, Patrick Smart, Jeffrey R. Broido, Kim Scholte|
|Source:||IEEE Std 802.3, 2000 Edition|
Copyright © The Hardware Book Team 1996-2004.
May be copied and redistributed, partially or in whole, as appropriate.
Document last modified: 2004-04-12