atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's Installing T1 from Demarc

I have been around the "normal" network cabling world and POTS stuff, but this is my first T1 job. I am going to bring up T1 service from the Demarc to a Cisco router. I am worried that the LEC hasn't put in RF45 jacks at the Demarc for me to plug into(then run a cable to the router) All that being said, if I have to install my own jack which lines will go under which screw terminal at the demarc? I know there are four wires, but what pairs are going to what terminal. Hope I havent confused anyone too much.

Thanks in advance,

Travis

The telco demarc is typically a smartjack. You just plug a patch cable in from there to your router.

Thats what I am hoping for...But if not? I would have to wire up some sort of a jack I think

The "smart jack" may be located on a small cabinet that houses cards in it. Most of the cabinets used by SBC and Verizon in my area will have 2 RJ45 ports underneath the cards on them. If there is only one card you will plug into the first RJ45 port usually labelled "1" or "a".From there you will plug a patch cable TO the WIC card on the cisco router.If you are too far to run a patch cable you will need to install a cat5 line from point to point. I usually then wire both RJ45 jacks as 568b and connect patch cables at either end.

You will get a green CD light on the WIC card that is in the router if everything is working correctly.

There is usually a small card in a pocket on these cabinets that will have your circuit ID on it.Verify your circuit I.D. as a matter of habit. I have seen guys banhg their heads againt the wall to find out they have been messing with the wrong circuit.

It's possible...T1 comes in normally on an RJ48C or RJ48X. RJ48X has shorting bars for when the cable is removed.
This uses pins 1, 2, 4, and 5.
1 and 2 are a pair, 4 and 5 are a pair.
Hope this helps!

In Rockford and surrounding area this is about the only way you'll see them now. The majority of T1s I deal with now are for subcontract work for national companies. The last three dozen (or more)T1s I have worked with have been installed in this matter.

The same thing at the last 12 Edward Jones locations I installed Cisco routers for.

I can't even remember the last time I connected directly to a "smart jack" for a T1.

Around here I only see smartjacks.

Wierd, I wonder why the switch in this area?
I was never in the DOG(changed names a few times) when I was at IBT/AMT/SBC/ATT so I can't say why they went from using the "smart jacks" to these. I should call one of my old co-workers and ask I guess.

I don't know a tremendous amount about the technical aspects of the T1 itself.Pretty much basics is all I needed to do my work with them. I did prep lines for circuit use and I have repaired the outside plant copper lines that carry them in.I've worked with guys on repeaters etc.Never really cared too much to be honest I have not actually installed one by myself. I do connect to them quite often in the course of the work I do now though.

I believe the ports in the cabinets are Rj48c. I'll take a picture of one and post it here so people know what I'm talking about.

An RJ48X is a smart jack. I think we are confusing this with a network termination unit or network interface unit. This is a card in a shelf or single mounting that belongs to the telco. Yes, the output of this card is considered a "smart" jack, but it can be extended beyond this point to another "smart" jack. The key is maintaining loopback.

The term "smart jack" just implies that it automatically creates a loopback condition between transmit and receive when the equipment is unplugged. That's all; nothing else. There are no cards that constitute a smart jack. For all intensive purposes, some circuits come into RJ48S jacks directly from incoming cable pairs. There's no magic going on. The card/shelf is only there to condition cable pairs from long loop lengths.

Ed, when I meant smartjack, I mean the cabinet on the wall with the special key and the circuit card. That's what I was always told they were called