atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's extending PRI demarc

I have extended T-1’s and PRI’s on cat3, cat5, cat5e, and cat5e shielded. I did however want to add to this thread that most cabling manufacturers make a specific cable for this application. If the customers are willing to pay, this is what we will always offer first, and in some instances (extensions over a few hundred feet,) it is all we will offer. Basically the cables designed for T-1 demarc extension have the pairs individually shielded. This fact is more important than the category of the cable.

Here is an example:
https://www.quabbin.com/finder/finder.cgi?cmd=display&cable_id=460

If the link does goes bad it is made by Quabbin...part number 9719

Also in Berk-Tek, part number 10032390

When T-1's were first being installed you had to use the shielded cable. I think that is now a thing of the past, at least as far as practice goes. I would have to agree that an extended DEMARC beyond a hundred feet or so, that it would be smart to use the shielded to cut down on electronic interference

I just got done running 50-pair for a 725' demarc extension yesterday. I need to extend the T-1, too (which will be a similar distance). What I'm gathering from this thread is that I can PROBABLY get away with CAT5E and perhaps some engineering inpur on the line buildout. Is this a correct assumption? Customer has been offered chance to use shielded cable and declined. I shouldn't have any unusual EMI issues on my cable path. Thanks.

Bill

That's quite a ways. Fortunately a T1 is more tolerant of low levels than hot, also a good CSU should have some gain you can build into it. If you've offered shielded and they declined, just make sure they are well aware that it may not work as expected. The shield was as much for keeping bleed over from the transmit receive path as for EMI, for that distance I'd sure push the shield.

Give the 50 pair a chance. Split the tx and rx between the bundles and don't forget to adjust the CSU line build-out. I'll assume you don't have a t-berd or other t1 tester so, have the service provider do a complete loop test to a CSU loop not just a 'hard loop' on the end of the wire pairs. A hard loop doubles the the length of the copper giving more line loss viewed by the tester. A 'head to head' test would be the best test but a 'soft loop' to the CSU should test fine.

Don't forget to see if the LEC tech will adjsut the LBO on the smartjack. Let us know what happens.

Just truned up a t1 from at&t that Verizon installed. Guess what, the trans and recieve were reversed from what they (verizon)told me. What a mess. They did the samething on the data t1. :bang:

T-1 extension came out to 740'; went live yesterday. So far, so good, but we'll wait until we get some traffic to call it good!

Thanks for the update. If you stressed it with no problem it should have no trouble carring traffic.
Bill