7

Nowadays, I usually make EIA/TIA-568A crossover cables for Fast Ethernet(10/100 Mbps) networks. On these cables, just 2 of the 4 wire pairs are used to comunications(the 2 remaining could be used for PoE or just for nothing), so I just needed to cross 2 color pairs(1-2 and 3-6 wires). However, on Gigabit Ethernet all the 4 wire pairs are used to increase the network bandwidth. So, to do a crossover on a Gigabit Ethernet I would need to cross all the 4 pairs. Is this feasible and reliable? I mean, how to make that and what is the correct color order of both ends of a Gigabit Ethernet crossover cable?

2
  • 3
    nowadays there is no need for such cables. You can use standard cable which supports 1Gbit (5E and upper) – bakytn Apr 9 '12 at 19:18
  • Just to be sure, you are running 1000BASE-T ? That's about 98% of hardware, but if you happen to be linking 1000BASE-TX the cross-over is the same as 100BASE-TX. – OCDtech Jan 14 '13 at 23:03
12

Wikipedia has pinouts for a gigabit crossover cable.

Note that while Auto-MDIX is an optional feature of the gigabit ethernet specification (IEEE 802.3-2008: "Implementation of an automatic MDI/MDI-X configuration is optional for 1000BASE-T devices"), most gigabit ethernet interfaces do implement it, so in most cases you will not need a special crossover cable.

3
  • same as 100BASE-T – OCDtech Jan 14 '13 at 23:04
  • 1
    it was my understanding that gigabit crossover is DIFFERENT from 100M and all 8 wires are a lot more twisted, and I remember that from a CISCO class I took years ago (and didn't used after ... always used a switch ... until now), also, I tested "normal" twisted (your webpage), even if network card report 1G connected, speed doesn't match up (I test transfer by moving data between ... ramdrives, on both computers just to be sure is not the speed of hard disk or something), and if I put a switch and non-crossover cables, then speed matches up – THESorcerer Jan 14 '16 at 13:48
  • For those wondering (and @THESorcerer), there is more than what that wiki shows. The crossover pinout for TIA/EIA-568b is: White/Green, Green, White/Orange, White/Brown, Brown, Orange, Blue, White/Blue. Note that the blue & brown are swapped (blue replaces brown) and twisted (solid replaces white/color trace). – Ruscal Oct 22 '19 at 14:50
6

You don't: Auto MDI-X is built into the Gigabit Ethernet spec. The endpoints will auto-negotiate and take care of those communication issues.

1
  • So the endpoints will always take care of it by default? – Diogo Apr 9 '12 at 18:44
6

For gigabit this is the pin layout you want to follow

PIN 1 - PIN 3 PIN 2 - PIN 6 PIN 3 - PIN 1 PIN 6 - PIN 2

So far this is a regular crossover cable. for gigabit use

PIN 4 - PIN 7 PIN 5 - PIN 8 PIN 7 - PIN 4 PIN 8 - PIN 5

For a color graphic guide follow the link below, is basically

ORANGE/WHITE ORANGE GREEN/WHITE BROWN/WHITE BROWN GREEN BLUE BLUE/WHITE

enter image description here

0
0

Your observation is correct. The solids always go to the solids, and the white stripe to the white stripe. The drawing is incorrect. The Tyco Products PDF instruction sheet is the correct way. See https://cdn.tycosp.com/docs/illustra.products/flex-mini-dome/Knowledge%20Base/Ethernet-Crossover-Cable-Gigabit_en.pdf

2
  • While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. – Donald Duck Jul 3 '17 at 18:04
  • getting access denied. Can you please mirror or copy here the relevant information? – Carmageddon Apr 2 '20 at 5:13
-1

Concerning a four pair crossover cable, for pairs on pins 1/2, 3/6, 7/8, the lower number pin is tip and the higher is ring (not to be confused with Transmit and Receive). However, in the 5/4 pair, 5 is tip and 4 is ring. This is indicated by the white stripe of each pair. Can anyone explain how 5 tip can crossover to 8 ring? The polarity of 7/8 would be reversed.

1
  • 1
    While this has some good content it is best as a comment NOT an answer – linuxdev2013 Jul 3 '17 at 3:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.