Extending a T-l DMARC:
---> Run data cable from T1 smart jack to where T1 needs to be (you can also extend by using 2 regular feed pairs but to start you off easy just file that in your notes)

---> Terminate cable on 8 conductor box jack near phone system or router & label with T1 circuit number

---> If Smart jack is modular, crimp a stright thru rj-45 end and plug into smart jack

---> Your T1 is extended and all you need is a straight thru patch cord or t1 crossover cable to patch the t1 to your equipment.

Lots of juice flows thru a T1 circuit which is why I terminate the extended end 1st.

The simple explanation for using feed pairs is to make connections straight thru and use pins 1 & 2 and 4 & 5 on both ends (smartjack RJ-45 and 8 conductor box jack).

Good luck...