atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Cross connects on a 66 block

Hi everyone!

I just found out that the analog phone lines at my work are now my responsibility. I am shaky on the concept of analog lines as I am used to VoIP.

For a 66 block, it is my understanding that feeder lines are punched on the outer lugs and cross-connects are punched on the inner lugs. I have color schemes for up to 100 pairs so I'm good there.

Here are my questions (feel free to laugh):
1. Say I have traced a wall jack back to a 66 block in the IDF. I have two other 66 blocks that go back to the MDF. How do I know which block to cross-connect to? The first available pair of (inner) lugs on the nearest block?

2. What do the numbers mean on the 66 blocks? At my old job they where like this: IDF.Block#.Pair# (15.2.37). All I see are numbers like 1376-1400. Is this normal?

3. What's a TN? If it stands for telephone number I'm so going to laugh at myself!

Thank you in advance for taking the time to answer my pesky newbie questions! :-D

1- I don't see any reason to skip a pair, unless analog and digital or circuits are kept separate.

2-1376-1400 sounds like 25 pair count in a house cable.

3- TN is probably Terminal Number out of a switch like a Meridian.

Here goes:

1. It depends. If there is/was a cable plan, you'd want to follow it. Those pairs going back to the MDF may be multipled elsewhere. If you check some of the other jumpers in the IDF you may get a feel for what was done. You can always just take the first vacant pairs if they are dedicated to that IDF.

2. Count. Yes it's normal. Somewhere there are 1375 other pairs run.

3. Start laughing. It might also mean Terminal Number, but we designate telephone number as TN=
around here.


Carl

Ah you're one of those... Don't worry you have come to the right place. We, most of us, are a gentle people. Here to help.

Correct

Possible answer one: Done that.
Possible answer two: No, no, don't worry, we will not make fun of you. *snickers in the background*


Let's see if we can all get on the same page here. When you say IDF (Intermediate Distribution Frame)I trust you mean this is a closet or place where 4-pair voice cables (the ones that come from workstaions, office, ect) terminate, and then there is a feeder cable to the MDF (Main Distribution Frame ie where your PBX is). If you have two "other" 66 blocks at the IDF these should be for the feeder cable. Sounds like these two are for a 100 pr feeder cable to the MDF.
In a perfect world the blocks would be marked so as the indicate their purpose, where they go. Alas, this is too often not the case and a problem even a seasoned phone person has to endure. If they are not marked you'll have to tone them out. Do have a tone generator and a wand? Otherwise, yes, the first available pair, like yo said.

1376-1400 looks right. That would a block of 25 pair, possibly part of the 100 pr feeder(?) On the other end of the feeder, in the MDF, you should find a block marked with the same numbers.

Do you have a Nortel phone system? If so, and if memory serves that Terminal Number. ie an extension. Been a while since I worked on one of those.

Oh my word!

Thank you Richard and Carl for your help!!! That clears up so much!

Some extra notes:
I do not have a diagram of phone or network lines. :-(
Yes, we use Notel's Meridian 1.
I do have a wand, though I am more familiar with toning out network lines than phone lines. Here's how I do it:
I plug my tone generator into the wall jack and run the wand down the clips in the IDF. If I find a strong tone, I kind of pull the wires to the side to mark where they are, grab two pieces of cross-connect, and replace the wires I pulled to the side. I put the two cross connect wires together. If the sound stops, I know I'm in the right spot. I put back (punch down) the wires I pulled out. Now that I know to look for the same number in the MDF, that's where I will go next to tone.

I'm still fuzzy on how the 66 blocks connect to the PBX (Meridian). I am guessing the feeder cable on the MDF's 66 blocks go into the phone swtich?

I am getting ready for work. If I don't respond quickly I apologize in advance as I will be stuck in traffic.

You guys have saved my life and that's no joke. I was literally losing sleep over this and becoming ill. Thank you again for all of your help, you have no idea how truly grateful I am!!! :-D

You're more than welcome. Do you only have one IDF?

If I were you, and I've been there, I would start keeping records of where all the cables are. Get a floorplan of your building and note the cable numbers (voice and data) on the floorplan. I have one big floorplan and then I break it down to smaller sections and keep them in a notebook. More than that I would start marking your jacks ... ON BOTH ENDS. You don't want to have to tone out every cable every time you go to work on them.

As for the Nortel, and this is true all PBXs, you have 25pr cables, connected to the backplane, coming out of the PBX and terminating on the wall. Do you really have 66 blocks? That's good. None of that BIX of 110 stuff ... These represent analog and digital phone port, and if you have any, copper trunks (outside phone lines). I think one 25pr cable per card slot on the Meridian. You may have some cables from the various terminating in the phone room. And, of course the feeder cables from your IDF(s) Cross-connect (no banjo string cross-connects please) from TN to the cable/feeder. Easy.

Hi Richard,

Sorry I didn't post sooner! I had a project that required me to stay on property.

We have several IDFs through out the property. I will get a floor plan of the building and begin breaking them into sections as that is a wonderful idea!

I do see where the 25 pair cables are connected to the cards in the Meridian. The 25 pair cables do run mostly to the 66 blocks. There is a section of 110 blocks (boo hiss!).

I'm sending you an email as I'd like to talk to you some more about this.

Have an awesome evening!!!