I have a question about extending a Bonded T1 past the Channel Bank.

Some boring background info:
We will be moving to a new building in January, so I have some time to get it all figured out.

Our phone service will consist of 5 POTS lines and a BONDED T1 line. In our case, 2 T1 Circuits.

I did an examination of the building already. It’s a 2 story multitenant building. We are on the second floor; with the ILEC Demarc on the first floor. There is already a channel bank in the demarc room, used by another tenant. We would be CKTs 2 and 3. The ILEC's policy is to save on equipment, so tenants share the T1 channel banks.

We have a 25 pair cable going between the demarc room and our suite. I spoke to the Verizon tech about what their wiring conventions are.

He said the obvious "we aren’t responsible past the Demarc", which wasn't my question.
I wanted to know what order/conventions were used for punching down the lines on 25 pair block to get them to the suite. And if we can use the 25 pair cable. for both POTS and T1's.

He went on to explain that it was perfectly fine to combine POTS and T1 service on the same 25 pair, since that is how their Out Side plant is wired. He then said that the POTS division would start by punching line 1 at the top White/blue, Blue/white pair and go down, on our block.
The T1 guys would start at the bottom with Violet/slate, slate/violet pair and work up.


My questions here are.

1. Has anyone seen this before?
2. Is this common?
3. By starting at the bottom, what would the pin out be</font><ol type="1">
4. Transmit then receive OR
5. Receive then Transmit.
6. Would you skip pairs?
7. Would you knowing that these are two circuits working together start with CKT 2 or CKT 3 from the bottom, or would it be the reverse of that.

[*]Or am I looking to far into this, and just do what feels right because there are no conventions to this.</ol><font size="2" face="Verdana, Arial">
Where would I go to find this stuff with out having to have been a Verizon tech in the past?

This is in the surrounding Albany New York Area, that may or may not have been NYNEX in the past, if that helps

Thank you all for any insight you can give. It is much appreciated.

A couple of questions:

I've never heard of a "Bonded T-1 Line". Is this like a DS1-C, some circuit with a bandwith of about 3 mbs that you will then split into 2 T-1s? Or are you using the 3mbs pipe as one ckt?

When you say "Channel bank", I think you mean a mux (probably a T-3 mux). A channel bank takes a 1.544 mbs T-1 and breaks it into 24, 64kbs circuits.

We try very hard never to run T-carrier on the same cable with POTS. When a T-1 is fed on copper OSP generally the transmits are put on one binder and the receives on another to minimize interference. If the circuit is coming over as a single pair HDSL or something similar, well, that's a different story.

Personally, we either used General Cable "T-1 Cable" or two runs of shielded 6 pair (transmits on one and receives on the other) to feed T-1s.

Sam

This is how it is billed by the carrier.
It's the bandwidth of 3Mb/s on two ckts. Both go into one router. It's our internet pipe, and our PBX uses VOIP to a Co-location.

To Quote Internet dot com
https://www.webopedia.com/TERM/b/bonded_T1.htm
You are correct, I am using the wrong term here, and I do apologize.
I mean this thing
https://picasaweb.google.com/lcdpanel/T1Box#5277859238743074210

Is that what this is called? a Mux?
Multiplexer?

It's a nice picture, but I have no idea what it is. Forgive me, but I've never seen one of those before. It looks like it's got 4 handofffs so maybe it's a T-2 (6mbs). Of course I haven't seen a T-2 since Picturphone at the NY Worlds Fair, but who knows? Why not?

A mux or multiplexer takes a big pipe - like a 45 mb T-3 and will break that down to 28, 1.5 mb T-1s. An OC-48 mux will take a large fiber pipe and break it down into 48 DS-3s, etc.

A channel bank does the same thing but is the smallest of the muxes, using a T-1 as the "big pipe" and breaking it down into individual Dialtones or DS-0 circuits.

Sam

That box is at our current location.
There is one just like this at the new location.
The T1 Tech from VZ said that since there is already some one using CKT 1 we will be on CKT 2 and 3.

This next pic is of the backboard in the "new" office. You see in the bottom left a 2 Circuit version of the box.

https://picasaweb.google.com/lcdpanel/T1Box#5277879575721191842

I think I know what you mean now by channel bank, That is what those 'mux'en were called by a Verizon guy I talked to years ago, I had been using the same name since.

I think that the last tenet or their Carrier left a real "Channel Bank" at the "new" office.

It's that white box with the 25pair terminating at the Orange Demarc Block, right?

So, back to the cabling question. Is it not recommended to place them on the same cable as POTS or a definite NO NO?
I understand that this could cause some problems, but how badly? Is it worth running more cable? If so where can i get this 6-pair cable, if we do indeed run it?

So if you were to put them on the same 25 pair,
you would put TX of both circuits on the Violet Binder and the RX of both circuits on the Yellow binder.

I have seen some people glazing over this in a few threads. The consensuses that I have found were:

• Just use Network patch cable to go between the demux and the router.
• Put the TXs on one cable and the RXs on another.
• (your suggestion) put the TXs on one binder and the RX on another binder.

Seems to be that the it's better to put the wires of the same direction together in the same jacket is better than keeping the whole circuit together in the same jacket.

I just noticed that there is a forum for T1 questions, sorry about that. If it needs to be moved there please do. I don't like adding to confusion. Cabling seemed to be the best place for it.

The box in the bottom left corner is the smartjack.
The white box at the top looks like an Adtran channel bank.

Your first picture is the smartjack, that acts as the telco's end-point of the T-1 lines. The second picture is an Adtran channel bank, probably a 624 model.

Smart Jack another misnomer to me. :p

So you guys refer to the entire enclosure itself as the smart-jack. I thought the term SmartJack referred just to the jack.

So I should understand that smartjack and the mux can be considered the same thing then.

BTW when Verizon came for a vendor meet, he tore out the smartjack that was on the board. Due to the new "tariffs" in the area. So I will need to extend the T1 up there some how.

Am I going to subject it to a lot of interference by placing them on the same 25 pair as POTS?

If I were to run a separate line for the T1's, and to preserve the shielding; how would I accomplish that? i haven't seen an RJ48x jack box with a ground round the socket.

You are correct: The term "smart jack" is widely-misused. A smart jack is a simple RJ48X that forces a transmit/receive loopback condition whenever the connected equipment is unplugged.

The enclosure is just an equipment mounting that often includes "smart jacks" as their form of output. The mounting and associated cards are often referred to as a network termination facility. This terminology varies by region.

A T1 circuit is brought to the facility and usually ends at a network termination facility. From there, it's RJ48X "smart jack" output is routed within the building as necessary. It never hurts to end this cabling with another RJ48X.

You probably won't see an RJ48X jack with a ground, however there is nothing to stop you from wiring a ground connection to pins 7 and 8 if it makes you feel more comfortable.

I wouldn't perform this extension via existing 25 pair cable if I were you. At minimum, I'd run a dedicated 4 pair cable for each circuit. The right way would be to break out all of the transmit and receive pairs for each circuit and route them via separate cables as Sam mentioned (all transmits in one cable and all receives in another).

A mux is separate from the smart jack.

So by putting TX and RX on separate 4 Pair cables, it is conceivable to get up 4 T1 lines up to our suite on only 2 cables with little interference.

True. Shielded cable would be better though. If you run 2 unshielded cables side by side, you might pick up interference between the transmits & the receives.

Sam

Linux Tech, sorry for the slight detour, in the past, I've heard Verizon people refer to a RJ68 as a "dumb jack" anybody heard of such a thing?

Using STP cable will be a definite then.

Is there diagram for breaking out a group of T1s to separate cables?

All I am finding is just the jack pin out. RJ48X
I also see that those jack pin outs have Tip and Ring reversed from the normal USOC Jacks.


So if I wanted to make this capable of 2 additional T1s With a total of 4, could I put all 4 T1's on these 2 cables going up to the suite?
Again, the TXs on one cable and RXs on another, and using Shielded cable?

There is something called RJ48M (m=multiline) connector and cable used for multiple T1 drops. I know Lucent (Avaya) used to make them, among others. It's not the cheapest, as far as cables go.

The polarity of tip and ring makes no difference. All that matters is that you have pins 1,2, 4 and 5 wired properly. If you are interested in purchasing some of these multi-circuit blocks, please send me a PM and we can discuss this further.

I extend T1s in malls all the time. Telco drops them at the mpoe and we take it from there. I try to run a dedicated line for each one but if customer wants to use the house pairs then we try it out. If it works then we leave them, other wise we will install single pair T1 extenders that will push it to 3.5 miles or run a cable, this all depends on length. If running a cable will execced the cost of the extenders or length, we go with extenders as they run just under 1k. And have never had an issue with this. Label and mark all pairs used with customer info for referance later and for others coming in and doing service work for other customers later.

Just to clarify (or muddle) things further, the RJ48M cable is a 25pair cable with a D50 clamshell connector on one end (what people around here refer to as an "amphenol") and a harmonica of 8 RJ48C jacks on the other end. All pairs are individually shielded. Pairs 1+2 on the D50 go to TX/RX pairs on port 1 of the harmonica, pairs 3+4 go to port 2 of the harmonica, etc etc

EDIT: I was a bit wrong on the wiring. The above applies to the RJ48H connector (D50 to 12 RJ48C). In the RJ48M, the D50 end skips one pair per harmonica port. So the wiring for RJ48M would be:

pair 1+2 = port1
skip
pair 4+5 = port2
skip

etc etc

Never heard of that...are those still made?

Jeff, I'm pretty sure that if you google for RJ48M cable or jack you'll find something. Though most dealers don't know what it is, you'll have to explain unless you have the exact part#.

See the wiring in the following document, on page 18 of the document: BellSouth DS1 reference

We have two bonded T1s as well (for internet access). The "bonding" is done with-in the carriers (Verizon) network. Just treat these as two separate circuits, which they are. The way I do it is run jumper cables (Cat 5 patch cables) from the smartjack to one of those Leviton patch panels (the kind that attach to a 66 block bracket). Then I run Cat 5 cables to the computer room and terminate the cables to patch panel. From there the IT guys plug into their magical router. A box too lofty for me... Basically I do it same as any ethernet connection on our LAN.

PS we are moving away from the two T1s and to an AT&T 10Meg MetroE circuit. More bandwidth and cheaper.

Could you come back to this with your Metro ethernet experiences once it gets going? (Service, equipment etc). I have no experience with ATT MANs and would like to know how it stacks up compared to smaller providers (I've worked with a couple of CLECs in installing Ethernet First Mile at customer locations, no big problems so far, and you can't beat the price).