atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's Cable from Smart jack to T1 module on 2801 router

We have a new circuit, and I thought they used a cat5 e from the smart jack to our T1 card on the router but it has a label on it from custom cables. I had to have someone run a wire at another site for a new circuit there, since the router there will be away from the telco mdf in the server room, I thought it would be a normal cat5e, but he said it should be a shielded T1 cable since it just sends and receives on the T1, this sounds right from what I remember but I wasn't sure.

Any comments

Thanks.

Shielded used to always be recogmended for T-1, not so much any more. It sure can't hurt for the few cents more you'll pay for the cable.

I think the one he used only had 2 pairs. It just through me a curve ball because I thought the other one was a 5E shielded and I am use to having 4 pairs on a network wire, and this T1 wire he ran was not 5E,he said it was a T1 shielded, which is what I want to run from the smart jack to the router, that it only needed the 2 pairs for send and receive to the router, this did ring a bell but its been a while since I had to deal with T1 wiring.

Thanks,

Networks use pins 1, 2, 3 & 6. T1 uses pins 1, 2, 4 & 5. You can probably use CAT5 for the DEMARC extension with no problem. I have read some arguements for using T1 wire, where the pairs are individually shielded (https://www.dcbnet.com/notes/0301t1.pdf -- also includes mfg part #'s). Regardless of what you use, maximum distance from the smartjack to your equipment is roughly 200m or 667 ft.

Thanks guys, now that you state the pin outs I think that answers my question. The one cable we used from the smartjack to t1 at another site custom made by custom cables so If I remember the wires are different so that makes sense.

Thanks Guys

If you are coming off something Like a CBeyond T1/router/Voip box you have to make a T1 crossover cable.

Em, its coming off the smart jack going to the router T1 module, on the 2801, WIC 1 DSU-T1 V2, the port says T1 CSU/DSU.

I didn't think that needs to be a cross over

Than you are good to go.

The proper way is to use an actual T1 cable. Usually they are a bigger gage wire and they are shielded. But if you have to, a standard patch cord will work; it just depends on the distance you are extending the T1.

Years ago that is what SBC/PTT required if you wanted to extend the circuit more than , I think it was 100' from the demarc . The cable was 2pr either 22 or 20 gauge and each pair where wrapped in a shield and there was a drain wire . The cable was very expensive . I remember on one job where we where extending about 300' they forced us to run 2 "T1" cables 1 for xmit and 1 for rcv . They don't seem to care now , we just run 2 25pr cat5 to the demarc for t1's and they place their niu or smart jack where ever the work order says to place it . Within reason of course .