Moving copper service

THE SCENARIO Our office demarc is located in a furnace room, along with our legacy pbx and alarm system base. All service is currently provided by a whole bunch of pots lines. Our new phone system will live in our server room's 19" rack and recieve PRI T1 service, but we still plan to have a few (probably 4) copper lines available to the new system. This means we need to either move or extend the copper service from the furnace room to the server room. One of my goals is to remove the furnace room completely from my cabling/IT infrastructure, and have everything terminating in my server room. This would mean getting direct cable runs from the building demarc to my server room, and it would mean moving the alarm system base.

MORE ABOUT THE DEMARC Our office fills about the front 1/3 of this single-level building. There is a demarc for the whole building, and feeder cables extend from it to the respective "private" demarcs contained within each office. Our demarc fits this description. One thing of note; the service to our office demarc appears to be provided entirely by individual runs of cat3 or cat5 cables; I don't see any 25-pair cables used, there's just a big bundle of wires coming down from the cieling to 66 blocks.

(Very) rough sketch of our building: ======================================================= | Building %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| | Demarc %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| |%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| |%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| |%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| |%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| |%%%%%%%%%%%%%% OTHER OFFICES %%%%%%%%%%%%%%| |%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| |%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| |%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| |----------------------------------\\%%%%%%%%%%%%%%%%%%%%%%| |%%%%%%%%%%%%%%% | %%%%%%%%%%%%%%%%%%%%%| |----------\\%%%%%%%%%% \\-----------------------------------------------| | Furnace |%%%%%%%%%%%--------%%%%%%%%%%%%%%%%%%| | Room |%%%%%%%%%% | Server | %%%%%%%%%%%%%%%%%| |---------- /%%%%%%%%%% | Room | %%%%%%%%%%%% Employee | |%%%%%%%%%%%%%%%%-------- %%%%%%%%%%%% Entrance | |%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| |%%%%%%%%%%%%%%% OUR OFFICE %%%%%%%%%%%%%%%| |%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%| ======================Front Entrance=======================

OPTION 1 Run 25 pair cable from the furnace room to the server room. This is probably the easiest option. It would be a simple matter to punch down the pairs to the unpopulated row of terminals on my 66 blocks in the furnace room and punch the other ends down to 66 or 110 blocks in my server room. In that scenario service could exist simultaneously at both locations until cut-over, which is a must-have. What I don't like about this is it creates another set of termination points, meaning another potential point of failure.

OPTION 2 Run new 25 pair cables from the building demarc to the server room. I like the single unbroken run provided in this scenario. But since service must be maintained to the old system until cut-over, this would mean I'd have to keep the existing runs from the building demarc to the furnace room, at least until the cut-over, or I'd have to run feeder cables from the server room back to the furnace room. That seems like a big waste.

MOVING THE ALARM Our alarm system base communicates wirelessly with its sensors around the building and with the alarm keypad. Its current location is in the furnace room, and the alarm keypad is located at the employee entrance. This arrangement is less than optimal for two reasons: 1) There's a large amount of metal ductwork all around the furnace room, and 2) the furnace room is located on the edge of the building; not central at all. In fact we have occasional trouble with the system because certain sensors will fail to check in with the base, and we think it's because of the distance from the base and the lack of a clear signal path to it. Moving the alarm system to the server room should improve the operation of the system because there are fewer major obstructions to signal, and it's more centrally located. At least, that's my theory. Of course the alarm requires direct access to a copper line, which will exist in the server room, either by moving the office demarc or by runing feeder cables from the existing office demarc.

That's about it...I'm looking for comments and suggestions on how others would approach this, and whether I've attached proper importance to some of my goals. I just want to do what makes the most sense in the long run while still being viable & practical in the short term.

Thanks in advance,


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Your rough sketch looks very rough on my computer :-)

You don't mention the type of house cable. Is it going away for a network based phone, or are you still needing to interface your new PBX in the server room to the house cable back in the furnace room?

It's not unreasonable to use option#2 to feed the demarc directly to the rack, and a feeder back to the furnace room for the existing stations. As you add or get time, you will repoint the stations to the server room. I'm guesing a single 25 pair to each location would be plenty. It's customary to run a seperate 4-pair cat 5e for the T1, but it's not necessary.

SInce you are rack mounting the PBX, you might build the frame on the rack. Try searching for 110 rack mount blocks on Google for sources. A one space 100 pair mount would cost about $20 plus the clips.

Carl Navarro

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Carl Navarro

Heh, I played with that for a while trying to get something that'd look consistent in plain text. Guess it didn't work! I've never tried to attach a pic to a ng, but I'm assuming I'd have to do it as a binary or something? Which is why I didn't try, but it'd sure make things easier!

The new system is VoIP, so the new "pbx" in my rack will simply be a few servers.

A question; what you do mean by house cable?

To clarify, currently our phone stations run on traditional cat3 wiring to the office outlets, and the phone pbx receives it's plain copper phone lines also in the form of multiple runs of cat3 cable. I'm guessing the phone system started out with maybe 6-8 copper lines in the beginning, so they did individual runs for each line. As their needs grew, they probably added lines a couple at a time until they ended up with a bunch of single cat3 runs. If the same job were to be done today I'm sure they'd just run a 25 pair cable and be done. And yes, the new system will need access to a few of the old lines, but the old system will need them too until we have cut over to the new system.

More clarification: the T1 service will actually be delivered over fiber, which will also be run straight into my server room. The old phones run on cat3, the new phones will run on our data network infrastructure. So cutover won't happen a bit at a time; everyone will start using the new system at once.

I just thought of something: couldn't I use option 2 to run 25 pair from the building demarc straight to the server room, but leave the existing runs to the furnace room's demarc untouched? Then feeder cable between the server and furnace rooms wouldn't be necessary. Once the transition to the new system is complete, the furnace room demarc could simply be disconnected from the building demarc, I could pull all the blocks and other crap off the furnace room walls, and coil the wires up in the cieling.

I'll search around, thanks for the tip.


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I've read this post and have a few comments/questions. It sounds like you might have a handle on things - but I'm going to pretend that you are ignorant - just to be safe.

1) You say that there is no 25 pair from the D-mark to the furnace room, but that there are "a bunch" of cat3 cables that were likely installed over time instead. That may be the case, but when you say "a bunch" it sounds like there may be a number of user ports fed by these cables - rather than POTS line feeds. It would only take 6 cables to get 24 pairs from the dmark and they are most likely punched to the same block. 6 cables doesn't sound like "a bunch" to me.

2) It sounds like you will need a multi - pair cable from the D-mark to the server room when you make your change over later. Maybe not. However, if your new service is going to come in on a fiber, will it have battery backup to supply analog devices (emergency phone, alarm, fax, etc...)? I'd want the security of POTS lines for these things.

3) What do you mean when you say "demarcs contained within each office"? Are you talking about user interfaces or are you talking about some kind of cross-connect? "demarcs contained within each office" sounds like really old cabling for a really old PBX that may have required 25 pair to each phone.

4) At the end of the old message you mention "coil the wires up in the ceiling". Not having seen this property, but surmising from your message, I don't like this idea. If my guess is right, when you get done with the changeover, there will be a lot of abandoned cable in the ceilings. This may even be plenum space with cables so old they have PVC jackets. This is a real threat to life-safety! In 2002, the NEC added removal of abandoned cable to the Code book, because so many ceilings are packed with this stuff (and it's lethal in the event of a fire). Here's a summary of that new rule:

*********** Abandoned cable is defined as "installed communications cable that is not terminated at both ends at a connector or other equipment and is not identified for future use with a tag." PVC insulated cable produces lethal smoke when exposed to fire. Plenum cables produce smoke in a fire, but requires more heat to begin to emit noxious fumes. Either way abandoned cable posses a life-safety issue and the owner of the building can be fined when officials find offenses. The code also indicates that the cable only needs to be removed from accessible areas. This means walls don't need to be opened or removed to get rid of abandoned cable. ***********

5) In most places where there is a warehouse, the "alarm" panel is for security AND FIRE. The fire alarm had to be installed by a licensed installer. This can be moved, but you better know what your doing! Worst case scenario, leave it where it is and move the transmitter, if that's possible. The transmitter is likely only for the security.

7) Second, on the alarm. If you do move it, be sure to get the same phone lines hooked back up to it. Watch for "shared lines" that are on the alarm system and be sure they get hooked back up properly or the alarm won't be able to seize the line in the event of emergency.

8) Lastly, I'm assuming that the cabling infrastructure is prepared for the VOIP. This means cat5 or better and (at least from what I've seen) either POE switches or power outlets near each phone.

Good luck

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Now that you mention it, I realize you're absolutely right. I've been so used to thinking of my server room as the origination point for all end jacks I completely forgot about that minor (!) detail. (My server room is in one place, the legacy phone system is in another.) Those wires will be used until we've cut over to the VoIP system, and then they'll be superfluous.

Yes, everything in my rack is on battery backup, and with the addition of the phone system to my rack, I'm going to beef it up considerably. In the event of a prolonged outage, I can shut down equipment that's non-essential for basic communications and keep the phone system running for quite a while. In a pinch I can also have my phone system programmed to fall back to it's few copper lines if the fiber goes out, and I can always plug a regular phone line straight into one of the POTS lines if necessary. I won't be without at least a few POTS lines...what you said about security and all.

What I mean is, there's the building demarc, but each office has a 66 block (or several) on a wall somewhere that feeds off the building demarc, and that "local" 66 block is where they punch down all the lines for their particular office. It could be that my use of the word "demarc" wasn't appropriate for that scenario; I don't honestly know.

Good, now I have a good reason to justify to management why I'm having the phone company come out to remove the old cable. I don't like leaving that kind of clutter around; I've already stipulated to the cabling installers that'll be running all the new cat6 wire in our office that I want the old wire pulled out after cutover.

I wouldn't be doing this myself; I'd have the alarm company move it. If they refused to do it, then I'd know it wasn't a good idea and leave well enough alone. The smoke/fire alarms communicate with the alarm base wirelessly just like the other alarm sensors do, if I'm not mistaken.

I plan to give the alarm the same phone line, but again, I'm not gonna do a damn thing with the alarm system without the alarm company's participation and blessing. I don't want to do it, I want them to, so everybody knows it was done right.

After our recabling project, it will be, and yes, we'll be pushing the phones with PoE switches.



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