Gigabit over copper crossover cable

Cabling-Design.com FREE cabling and networking Helpdesk
icon
 Question by Ryan Lundebrek posted 21 Sep 2000
 Gigabit over copper crossover cable
I am trying to find out the pin assignments to make a Gigabit over copper crossover cable. Where can I find this information?
icon
 Answer by Roman Kitaev posted 25 Sep 2000
Hi, Ryan!

Thanks for interesting question. Following it, I looked for an answer into the 802.3ab 1000Base-T standard and found the following:

The 1000Base-T network card uses the following pinout in its port:

Contact Signal
===========================
1 BI_DA+
2 BI_DA-
3 BI_DB+
4 BI_DC+
5 BI_DC-
6 BI_DB-
7 BI_DD+
8 BI_DD-

The 1000Base-T switches and repeater use the following pinout in its ports with internal crossover:

Contact Signal
===========================
1 BI_DB+
2 BI_DB-
3 BI_DA+
4 BI_DD+
5 BI_DD-
6 BI_DA-
7 BI_DC+
8 BI_DC-


Following these pinouts, the wiring for a 1000Base-T crossover cord will look like shown at this link:

http://www.cabling-design.com/references/pinouts/1000base_t_crossover.shtml

When making this crossover cord, please take into consideration that 1000Base-T standard states:
"Implicit implementation of the crossover function within a twisted-pair cable or at a wiring panel, while not expressly forbidden, is beyond the scope of this standard".

Best regards
Roman Kitaev, RCDD

Click here to see the expert's profile
Back to the current page of questions | Back to all the questions
Back to Cabling-Design.com HELPDESK | Ask your question
Residential Cabling Guide

Home Cabling Guide

Finally, an instantly downloadable book that saves you thousands in home improvement dollars! Enjoy living in 21st century technology-advanced home while increasing its selling value and competitive advantage on the real estate market. Whether your cabling is for home office or high-tech leisure, you can wire your home yourself or learn "wirish" to speak with your cabling contractors in their language!

Learn more ...

Please rate this page

Rating: Average rating: Ratings
BadFineGoodVery GoodExcellent