Splitting a CAT5E (or better) cable between two T1 or E1 circuits

Click here to go back to the list of pinouts

Splitting a CAT5E (or better) cable to extend two T1/E1 circuits

back to the list of pin layouts

Every once in a while there is one too few cables between your customer's POP (point of presence) and their equipment room. We suggest a solution here that is in no way standard although known to work on distances not exceeding 500ft ( approx. 150 m). The actual choice of pairs (especially for the second RJ48) is completely optional for as long as you keep the transmit and receive pairs as such - a twisted pair. Do not split the pairs - this will very effectively kill the signal within short distance from the smart jack. Use at your own risk.
Splitting a CAT5E cable between two T1/E1 circuits. Straight-through cable

Splitting a CAT5E cable between two T1/E1 circuits. Straight-through cable

Some customer equipment requires a cross-connect T1 cable: transmit and receive pairs are swapped on the other end

Splitting a CAT5E cable between two T1/E1 circuits. Crossover cable

Splitting a CAT5E cable between two T1/E1 circuits. Crossover cable
 


T1/E1  RJ48 Pin Assignments

8P8C (RJ48) Pin Number Wire Color Signal Description
1 white/orange Receive Ring (RX)
2 orange/white Receive Tip (RX)
3 Pin not used
4 white/blue Transmit Ring (TX)
5 blue/white Transmit Tip (TX)
6 Pin not used
7 Pin not used
8 Pin not used


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 ...