atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's Extending AT&T T1 Demark

I just had AT&T install the T1 loops to their punch pin demark. Now it needs to be extended to the RJ-48 jack in the computer room.

I understand that the receive pair should be on lines 1 and 2, and the transmit pair should be on lines 4 and 5. The question is: how do I determine which pair on the punch-block is transmit and which is receive?

If it means anytime, one of the pairs was cross connected by AT&T to the cable going to the computer room, but the other. Or, perhaps the fact that one pair is near the top of the 50-pair block and the other is near the bottom?

Thanks!

They should mark them TX and RX...sometimes they actually do it...

Without a test set you cant tell. Run the circuit out and if it doesn't come up reverse the pairs.

But wait! AT&T should be giving you the T-1 on a smart jack or at least on an RJ-48X NOT on a punch block. (I don't think they've used DB-15s in 20 years).

Sam

Yes they should give you a jack as Silversam said. If they do it as has been industry standard from the beginning, the low pair is the receive. Now this is from an old telephone man that was brought up to do it right. I can't guarantee that the new guys were brought up to follow this standard.

Interesting, Bill...I never knew that about the pairs.

Jeff, the first pair was always the customers receive, no matter what kind of 4 wire circuit, that's the way I was taught. Never had to guess.

AT&T is getting very lazy. I got one on a punchblock today.

Yup, we've been getting them on 66 blocks at some jobsites in the last couple of years too.

Guys -

If you've been getting them on punchblocks - then how do they test them remotely?

I guess they can't.

What are these people doing to my industry.


Sam

They have to have something on it to condition the line I'd think.