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A subcontract job I'm doing includes extending the T1 from the demarc
to the telco equipment wall in the tenent's office suite. The
contractor has provided CAT5e UTP and jacks for this purpose. From
what I gather, this is not the proper cable to use, and I should be
using either a cable with individually shielded pairs, or two separate
cables, each with an overall shield - one for transmit and one for
receive. Is this correct?

Also, from what I gather, the pairs in use are 1&2 and 4&5 on an
8-position jack? So, using the UTP provided, I wired the extension as
T568B at both ends. Aside from any issues that arise related to my
first question, should this work?

You can use the Cat 5e cable, though using the shielded cable is the
right cable to use. The cat 5e cable will cause more bit errors than a
shielded cable, but, it will still work. A lot of talk has been on here
before about it. You may want to use Google and search for more info on
this cause I know there is a lot.

Michael Quinlan wrote:

A subcontract job I'm doing includes extending the T1 from the demarc
to the telco equipment wall in the tenent's office suite. The
contractor has provided CAT5e UTP and jacks for this purpose. From
what I gather, this is not the proper cable to use, and I should be
using either a cable with individually shielded pairs, or two separate
cables, each with an overall shield - one for transmit and one for
receive. Is this correct?

The absolute very best cable to use is what you describe, individually
shielded twisted pair cable. This is also referred to as T-1 screened cable.

Now back to the real world.

I install and extend special circuits for Verizon every day. We use
Cat-5 cable for nearly all demark extensions nowadays. There is nothing
wrong with using Cat-5 cable for T-1 extensions. Cat-5 cable works fine
for 100 Megabit ethernet signals, a 1.5 Megabit signal should be no
problem at all.

I've also installed and extended T-1's on regular 25pair cable with no
problems at all.

Also, from what I gather, the pairs in use are 1&2 and 4&5 on an
8-position jack? So, using the UTP provided, I wired the extension as
T568B at both ends. Aside from any issues that arise related to my
first question, should this work?

Unless the environment is very EMI/RF hostile, or the extension is
*very, very* long, you should be just fine.

And yes, a T-1 circuit uses pind 1&2 and 4&5 the other pairs are unused.

John
--
John P. Dearing
A+, Network+, Server+
To reply: Just drop "YOURPANTS" in my address! 8-)

Verizon used a 50-pair cable to extend 10 POTS lines into the suite,
leaving 40 pair unused. I offered to use 4 of those to extend the T1,
but the contractor wanted me to run a new CAT5e cable instead.

Thanks for the quick replies. Now I feel more comfortable going back
on site tomorrow.

I did take a look. But my searches yielded a lot of unrelated
messages, as the search term "T1" brought up almost all references to
ANY wiring scheme, because of pair 1 being T1 & R1, pair 2 being... you
get the idea.

Michael Quinlan wrote:

Verizon used a 50-pair cable to extend 10 POTS lines into the suite,
leaving 40 pair unused. I offered to use 4 of those to extend the T1,
but the contractor wanted me to run a new CAT5e cable instead.

Thanks for the quick replies. Now I feel more comfortable going back
on site tomorrow.

What I would do if *I* was presented with that situation would be to
split the T-1 between the two binder groups in the 50 pair cable. Put
one side of the the T-1 in the white/blue binder and the other side in
the white/orange binder. You only need two pairs for the T-1, not four.

Back in the old old days, T-1's were always put in separate binder
groups to reduce cross coupling between transmit and recieve. Just make
sure to clearly tag and protect the pairs you use for the T-1.

You really don't *need* a Cat-5 cable for T-1. It's only 1.5 Mb/s. Using
Cat-5 is nice, but overkill.

As I said before, I install and repair these circuits every day. I've
extended T-1's through over 1,000 feet of house cable and had the
circuit work absolutely fine with no errors whatsoever. House cable is
Category *nothing*. 8-)

John
--
John P. Dearing
A+, Network+, Server+
To reply: Just drop "YOURPANTS" in my address! 8-)

Michael Quinlan wrote:

I did take a look. But my searches yielded a lot of unrelated
messages, as the search term "T1" brought up almost all references to
ANY wiring scheme, because of pair 1 being T1 & R1, pair 2 being... you
get the idea.

Try DS1.

What I would do if *I* was presented with that situation would be to
split the T-1 between the two binder groups in the 50 pair cable. Put
one side of the the T-1 in the white/blue binder and the other side in
the white/orange binder. You only need two pairs for the T-1, not
four.

Back in the old old days, T-1's were always put in separate binder
groups to reduce cross coupling between transmit and recieve. Just
make sure to clearly tag and protect the pairs you use for the T-1.

You really don't *need* a Cat-5 cable for T-1. It's only 1.5 Mb/s.
Using Cat-5 is nice, but overkill.

As I said before, I install and repair these circuits every day. I've
extended T-1's through over 1,000 feet of house cable and had the
circuit work absolutely fine with no errors whatsoever. House cable is
Category *nothing*. 8-)

John

CAT 5 cable should not be a problem when extending a T1 from a DEMARC .
It is not the cable itself that determines the cable selection/design.
Rather it is DS1 signal loss that determines if TX/ & RX pairs must be
isolated from each other.

With a 0.0 to -7.5DBDSX T1 hand off level by the Telco at the DEMARC, A
T1 can be extended for a reasonably long distance as long as the
insertion losses of the cable @ 772KHz are not excessive enough as to
allow signal cross talk from one transmission pair (Strong signal) to
the other (Weaker signal) to occur.

Twisted 25 pair cable is OK for relatively short runs, however if used
on house riser, it is reccomended that different 25 pair binder group
pairs be used to isolate T1 RX/TX pairs.

Bill

Michael,
take a look at the knowledge base article # 2374 on Kentrox's web site. it covers this issue very well.

www.kentrox.com
service and support tab
Tech Support Knowledge Base
search for 2374.

I too am subcontracting a job that I now find out I have to wire from the dmarc to inside. That being said, I would like to do is get a full understanding of the wiring. So as I understand you, 1&2 go to the red & green, and 4&5 go to the yellow & black. Is that correct, and does red go to 1, green to 2, yellow to 4, and black to 5? Please help.

PsycoDaD wrote:I too am subcontracting a job that I now find out I have to wire from the dmarc to inside. That being said, I would like to do is get a full understanding of the wiring. So as I understand you, 1&2 go to the red & green, and 4&5 go to the yellow & black. Is that correct, and does red go to 1, green to 2, yellow to 4, and black to 5? Please help.

If those are the colors of your conductors then you have "quad" and not twisted pair. You are asking for trouble down the line without the twisted pair construction

JoeGolan wrote:

PsycoDaD wrote:I too am subcontracting a job that I now find out I have to wire from the dmarc to inside. That being said, I would like to do is get a full understanding of the wiring. So as I understand you, 1&2 go to the red & green, and 4&5 go to the yellow & black. Is that correct, and does red go to 1, green to 2, yellow to 4, and black to 5? Please help.

If those are the colors of your conductors then you have "quad" and not twisted pair. You are asking for trouble down the line without the twisted pair construction

I have to extend a T1 that comes in on a standard modular to 4 post nid. R-G-Y-B. Which of these colors goes to which pin on a standard RJ-45 and should it be punched 568A or B? I have to run a cat 5 from the RJ 45 jack to a Cisco 1841 with a DSU card.

RacePixRich wrote:

JoeGolan wrote:

PsycoDaD wrote:I too am subcontracting a job that I now find out I have to wire from the dmarc to inside. That being said, I would like to do is get a full understanding of the wiring. So as I understand you, 1&2 go to the red & green, and 4&5 go to the yellow & black. Is that correct, and does red go to 1, green to 2, yellow to 4, and black to 5? Please help.

If those are the colors of your conductors then you have "quad" and not twisted pair. You are asking for trouble down the line without the twisted pair construction

I have to extend a T1 that comes in on a standard modular to 4 post nid. R-G-Y-B. Which of these colors goes to which pin on a standard RJ-45 and should it be punched 568A or B? I have to run a cat 5 from the RJ 45 jack to a Cisco 1841 with a DSU card.

OK... I got it.

Black to White/Orange
Yellow to Orange
Green to Blue
red to Blue/White

I am wiring an Audio Codes to a PBX telephone system. I am using a straight through Cat6 jumper from the RJ48x to the PBX. What would the Cat6 from the Audio Codes to RJ48X color code be? I know that it must be wired as a crossover. I think I wired the last one:


White orange – 5 (green)
orange – 4 (red)
white blue – 2 (orange)
blue – 1 (blue)

Does this seem correct?