atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring RJ48 question - must have been asked before

Verizon is dropping off two PRI circuits in the MPOE of a commercial high-rise. I requested that they tag the lines and provide RJ48 jacks in the MPOE. I will extend the lines using existing house pairs from the 3rd floor MPOE to the 11th floor equipment room. Technically, the demarc is still in the MPOE right? I will leave their RJ48s alone so they can do loopback testing there. Then I will go from the RJ48 with an RJ45 cable, punch it to house pairs, ride into the equipment room and provide RJ45 jacks by the routers. I have done this a million times. Is it technically correct? Should there be RJ48s in the equipment room too?

This is too funny! Take a look @ Ed's post under '1A2 and Comkey' "Can anybody tell me why" The 2 references he has are going to tell you that you are asking a repetitive (?), or maybe circular, question. I hope you see the humor in it. I'm NOT trying to harass you, or whatever.

This one: 'posted 09 September, 2008 07:46 PM'

Man I wish I knew how to move stuff around. These new-fangled typewriters will be the death of me yet! John C.

Any T1/PRI circuit should be terminated on a jack wired with the RJ48X pattern so that it stays alive (looped) when the CPE is unplugged. John is right, you should refer to this link for better clarification: RJ MISCONCEPTIONS

If you're getting 2 PRI circuits and you plan on running "Rj45 cable" which I assume to be 4 pair, I would suggest that you put both transmits on one cable and both receives on the other cable. When you get to the MPOE, break them out there, and yes, put RJ-48Xs in the equipment room too.

Sam

Ok, I've got to ask...

Why put them on the same cable?

Thanks!

Justin

Well, in a sort of easy-answer kind of way, the signals are going in the same direction. Both transmit pairs are heading up within one cable jacket and the receive pairs are heading down in the other.

Maximum separation between the transmit and receive pairs is the ultimate goal, but I always thought that was the purpose of never-ending tightening of cable pair twists under the same jacket to begin with.

The Jury is still out at my house on this subject as a whole. I think it's all about cable manufacturers seeking ways to scare people into buying twice as much cable.

I've never bought that concept, but it seems to be the industry standard so I'll stick with it as much as possible.

Ed beat me to it...

I've been working with T-1s for about 25 years. GTE was very big on them and I got a lot of real good knowledge early on. Later on during the dot-com boom I installed a huge amount of carrier,so I've got a lot of varied realworld practical experience with "T"s too.

GTE believed in running Transmit & Receives in the same cable but they would run a huge multi-shielded cable. It was an 8 pair monster from General Cable. Each pair was individually shielded and it had an overall braid and shield. An 8 pair cable was easily the size of a standard 50 pair.

During the dot-coms I installed T-1s & T-3s for AT&T, Winstar, Level 3,Teligent, Art and a slew of others. Most of those folks believed in 2 cables - one for transmits and one for receives. Usually we ran AT&T screened cable - either 6 pair, 25 pair, or ABAM.

Some of the folks we dealt with asked for their T-1s to be extended via Cat5 cable and we always obliged them. Our experience was that on runs over 50' we experienced significant errors.

Now perhaps our testing procedures were overly critical. They were real tough. We would use Sunsets or T-Birds and we would run 15 minutes of all "1"s followed by 15 minutes of all "0"s (if the circuit was B8ZS) followed by 15 minutes of 3-24 (or 2-23) and then 24 hours of QRS. Each test checked out a different part of the circuit. We were allowed ONE error in the 24 hour period. One error, no more. More than that, we had to rip the circuit out and redo it till it passed.

We would routinely pick up problems with the cables that had transmits & receives on them.

All I can speak to is my personal experiences.

Sam

Some of the folks we dealt with asked for their T-1s to be extended via Cat5 cable and we always obliged them. Our experience was that on runs over 50' we experienced significant errors.

That's not going to sit well with the CGs who insist on doing it that way.

-Hal

Most people don't have the equipment to test T-1s properly.

Most CG's worry about the LAN not the WAN. All they know is CAT5. They don't realize that the CAT5 extension of their T-1 circuit is an extension of the WAN.

If you install a T-1 improperly and have errors, how would you know? If it's not down hard then you still have service. Packets that fail are resent. Service is just slower. VOIP is where you'll see problems and that's a Voice issue, isn't it? Why shoud the CG worry about it? Just add more bandwidth.

My personal feeling has always been that if you don't have the tools and/or expertise to test the product you're putting in, you shouldn't be doing it.

But what do I know.

Sam