Rx and Tx

Cabling-Design.com FREE cabling and networking Helpdesk
 Question by kent z posted 26 Sep 2001
 Rx and Tx
why are the Rx 3 and 6 pin seperate but the Tx 1 and 2 pin together. for the enthernet cabling
 Answer by Dmitri Abaimov posted 29 Sep 2001
This is the layout that had been chosen to ensure backward compliance with RJ-11 and RJ-12 modular jacks. Pair number 1 is always in the center of the jack, which makes it possible to plug RJ-11 plug into RJ-45 jack and have analog phone working. Pair number two would be the adjacent conductors, so #1 gets in between. That's why pins #3 and #6 are separated. Pins #1 and #2 form pair #3 which happens to be outside reach for the older plugs, so they made one next to each other since I believe it was just easier to do.

Dmitri Abaimov, 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 ...