T1 Question Wiring 1

[mikey62]

Ok. I am looking at the 66 punch down block. I have a 4 wire or 2 pair T1 circuit that I need to connect to a biscuit or the Jack. what pin's(ex>1,2,3,6?) do I connect to on the jack? I am starting from top to bottom on the 66 block.

I will avoid this if they have left me a smart jack.

thanks.........Mikey

 

[daronwilson]

Well on the jack, one pair will be on pins 1 and 2, the other pair will be on pins 4 and 5. I'm unclear what you are doing with the 66 block in there, but if you are extending the circuit from one locaiton via a 25 pair and 66 blocks, just pick two pairs connect them up to the jack. Personally, I would use two pairs from different binders to get a bit of separation within the cable if you can. Maybe you can draw us a little bit better picture of what you are trying to hook up.

Good Luck! It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[mikey62]

Thanks Daron! your are correct on the 1,2,4,5 = is for an atm machine. Is CAT5 plenum needed versus no plenum? incase I have a smart jack and then I have to use a t568B to run about 50 to 75 feet.

thanks again.

Mikey

 

[bobsou]

pelnum,depends on fire code , all you need to extend is class 2 wireing , but every one likes cat-5 a t-1 is still a anlog line it comes from the telco as class 2 or 3 in the cable only after the router does it make a difference

 

[daronwilson]

Hmm, well the T1's we use are digital, not sure what you mean by the T1 is still an analog line from the telco, but the T1 is a digital circuit. It is generally delivered on two pair, though depending on the installation and equipment may use only one pair to the card with the smartjack. The type of wire from the CO to your smartjack may be level 3 or even worse, however, it has repeaters in the circuit and the card inside the smartjack housing does some equalization/amplification which make up for the signal degredation over distance.

So, the question often arises "what wire do we use to extend the DMARC?"

Optimum for four wire T1's, IMHO, would be two pair, individually shielded DS1 type wire. There are several vendors that make this product, and it works well for hundreds of feet. If you dont have this, you could put the transmit pair on one single pair shielded and the receive pair on another single pair shielded. If you dont have that, you could put a Cat5 jumper in there and go quite a ways.

Now, this always brings people in who make some claim like " I ran my T1 DMARC on Radio Shack Bell wire for 2000 feet just fine " or something. To this I say, great. However, if/when you have some network problems and are trying to track them down, that will likely be suspect. Unfortunately, buying or renting the test gear to test it would cost you dearly.

The point is, why would you risk it? Use the best that you can afford for the circuit. If you only have 20 feet to go, almost anything will do it for you.

The reason Cat5 gets used often is because it has tight twists, thus keeping the signals on their individual pairs of wires as much as possible, and well it is very easy to get ahold of and use. I've extended many of them by just terminating a piece of Cat5 with a modular plug at the smart jack, and a regular ethernet jack at the distant end with no problem.

Your success in extending the DMARC for some distance may depend on configuration and signal strength at the smart jack as well. We recently were called to extend one about 400 feet inside a building from the MDF to the computer room. Extending it would have meant DS1 type wire for a nasty pull. Instead, we just moved the smartjack and jumpered the T1 on the existing 100 pair Cat3 house cable.

Good Luck!
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[TouchToneTommy]

But getting back to extending a T1 from a 66 block to a jack: In my area, Pacific Bell will terminate the customer side of a T1 on a small 66 type block (it is a split block with only 3 pairs and a clip on plactic cover). They will designate one pair as Cust. Trans. (usually the White/Blue pair) and the other pair as Cust. Recv. (usually the White/Orange pair). If you run a piece of Cat-5 from there to the jack location, match the Blue and Orange pairs at the block, and put the jack down as a 568-B (orange on 1&2, blue on 4&5) you should be OK. I also made up a "crossover" with a jack and a 8-C pigtail to flip the blue and orange pairs for those times that the CSU/DSU doesn't come up and I suspect that the Transmit/Receive pairs are flipped at the 66 block. If it works with the crossover, I go back and repunch at the block.

HTH

 

[bobsou]

T-1 are anlog circuit sending digital signal
a PRI is a digital circuit

 

[daronwilson]

Hmm, well humor me, please explain the T1 being analog. As I understand it, both the T1 and the PRI/BRI are digital circuits. By definition, they send either a 1 or a 0 down the wire, and those digitial bits are built into the data stream. An analog circuit would require a modem to convert the analog signal into a digital signal for connection to a CSU/DSU.

Anyway, I'm here to learn too, please help me out.
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com

 

[franke]

You are correct Daren, a T1 (DS1 or Digital Signal level 1) circuit is 'digital' as originally defined by the ANSI T1.107 specifications. PRI is more of an application that is designed (programmed?) to run on the T1 circuit. A good example would be two switches connected with a point to point T1, the switches (not the T1) are then programmed as PRI.

franke

 

[evilcb]

http://www.combsnet.com/cable/Basics/66blocks.html