Network wiring discovery

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#1 Post by **carbon_unit** » Fri May 30, 2008 6:44 am

I have a client who is moving to a different building. The new (to them) building is already wired for ethernet but nothing is labeled. There are wall plates all around the building with 4 to 6 sockets each and 1 location with approx 60 sockets. No map, no labels, no pencil marks, nothing. Some of the sockets are red, some blue and some white.
Other than trial and error is there any procedure to determine what goes where?

#2 Post by **Kyocera** » Fri May 30, 2008 11:01 am

You need to get a toner or cable checker. I had one that you plug one end into the port and the other end into the patch panel and it generates a signal. I assume they have a patch panel right?
Is it punched down? If it is get one person with a one half of the checker and the other and trace down your ports. Make your own labeling scheme and then make a topology map and post it in the room where the patch panel is. It is kind of trial and error and will take some time.

#3 Post by **rkawakami** » Fri May 30, 2008 11:59 am

I bought something like this off of eBay a few years ago:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0226619889

Mine doesn't have the 10Base-2 BNC connector but essentially operates the same. You plug the smaller module (aka "remote") at one end of the ethernet cable and the main unit at the other end. A sequence of blinking LEDs then tell you if you, 1) have the right cable and 2) is properly wired.

ajkula66 · #4 Post by **ajkula66** » Fri May 30, 2008 12:11 pm

You may want to open one of the sockets and follow the colour-code. Better yet, open up one of the red ones, one of the blue ones and one of the white ones. Compare the wiring you find inside.

Normally, the colour code is:

1) white/blue
2) white/orange
3) white/green
4) white/brown
5) white/slate
6) red/blue
7) red/orange
8) red/green
9) red/brown
10) red/slate and it goes way further than this, but you hopefully won't need it..

Normally, the wiring is done in 4, 6, 12 or 25 pair wire. What looks to you like 60 sockets is probably 5x12 pair behind, or 2 hidden RJ 21x blocks with 25 pairs each.

Kyocera is absolutely right, you need a tone set and a tracer, or you'll go out of your mind. I've been doing this stuff as a big portion of my daily job for the last eight years, and it can be a PITA to trace someone else's wiring...

Tone set and tracer (aka probe) on eBay:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0233091977

One version of RJ21X jack (aka 66 block):

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0188816213

Good luck and feel free to drop me a PM if you need help with this...

Moderator edit: Shortened URLs to prevent horizontal scrolling

#5 Post by **Kyocera** » Fri May 30, 2008 12:11 pm

Ray, that is very similar to the device I use to carry.

Hopefully there is no bnc connections in the building!!

#6 Post by **rkawakami** » Fri May 30, 2008 12:28 pm

I've only used my tester to verify that the cables I build / find are correctly wired, either straight-through or cross-overs. It's easy to do when both ends of the ethernet cable are only inches apart

. For Carbon's client, it probably means an assistant with a phone or walkie-talkie who moves the remote around to the different wall plates/sockets, while he tries to find the matching outlet out of the group of 60.

#7 Post by **Kyocera** » Fri May 30, 2008 12:48 pm

Tim you can also buy sheets of labels that you can run through a laser printer to attach to the wall jacks, you could use a sharpie but I always tried to make mine as professtional looking and tidy as possible, that's how you get customer referrals too

Normally you use the "B" (pictured below the A on page)standard for wiring, I think that is what ajkula66 posted. If you do have to set up or make corrections to the patch panel you'll need a punch down tool also. Good luck it's tedious but kind of interesting stuff if you get it all working.

You do mentions different color covers on the wall jacks (I think) that usually denotes either a digital phone lines, or other type wirings for phone or analog ports. Maybe George could elaborate a little more on that part.

ajkula66 · #8 Post by **ajkula66** » Fri May 30, 2008 12:57 pm

What I've posted regarding the wiring is something else, since I'm assuming that there are 6/12/25 pair cables running in the background of the whole thing, unless someone has spent a ridiculous amount of money on wiring it like Kyocera assumes if I understand him correctly, which is CAT5 into CAT5...and this would be great for your customer, but not for you since you'd be running around a lot more...

#9 Post by **Kyocera** » Fri May 30, 2008 1:33 pm

ajkula66 wrote:unless someone has spent a ridiculous amount of money on wiring it like Kyocera assumes if I understand him correctly, which is CAT5 into CAT5

Actually I'm not assuming any particular configuration. Just passing along how I used to track down and set up wiring to facilitate a customers computers on their network. I don't have experience with IP phones analog phones or the like and have only worked with cat5 cat5e cabling so far.

#10 Post by **carbon_unit** » Fri May 30, 2008 6:16 pm

It is all cat5E 4 pair runs and a lot of it. They are all punched down as far as I seen so far. I'm familiar with the A and B wiring schemes. There is sort of a patch bay in that there are a bunch of wall plates in one room with lots of sockets. They probably spent more that a patch bay would have cost. This building was occupied by a competitors computer shop that went out of business. Looking at the wiring they did on their own building, I can see why they are gone. Now I get to clean up another one of their messes.
I'll get a toner and a tracer but I bet the client will call me before they can get here. I seen them moving equipment today when I drove by. I bet the phone rings early Monday morning.
Hmmm...Maybe I better skip ebay and find one in a store this weekend.

#11 Post by **carbon_unit** » Fri May 30, 2008 6:50 pm

I found this on ebay. It is a bit pricey but it is located close. I could get it overnight. The job will pay for it with plenty left over.

ajkula66 · #12 Post by **ajkula66** » Fri May 30, 2008 6:53 pm

carbon_unit wrote:

It is all cat5E 4 pair runs and a lot of it. They are all punched down as far as I seen so far.

You lucky man. I guess I'll have to move to North Carolina or Iowa if I want to work on the stuff that is done properly...granted, you may have to run around a bit more, but it's sooooo much cleaner and so much easier than the unholy ways people do stuff like that in NYC...I'm jealous...

Good luck with this project and keep us in the loop, will you?

#13 Post by **Kyocera** » Fri May 30, 2008 6:56 pm

That would be about perfect, little pricey but it will definately do the job and then some.

#14 Post by **rkawakami** » Fri May 30, 2008 7:18 pm

carbon_unit wrote:I found this on ebay.

That one would be very useful for the crosstalk and length measurement capabilities (if there is the possibility that the cable runs exceed the 90-100m maximum spec). I found my cable tester here at work:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0032997676

I think I paid about $10 for it a couple of years ago. Real simple... plug a cable between the master and remote, slide the power switch on and watch the 8 LEDs light up in consecutive order on both ends (for straight-through cables).

#15 Post by **carbon_unit** » Fri May 30, 2008 7:58 pm

I could make do with one of those simple testers but I need something quick and that auction was the closest thing i found on ebay. The extra features would be nice but not necessary.
I thought I had a few days to get some equipment but I got swamped today at work so I couldn't look for equipment. Then I seen those guys moving the computers already.

I better drive to the city and find whatever I can find on a Saturday to get the job done.

#16 Post by **carbon_unit** » Sun Jun 01, 2008 9:11 pm

Couldn't find anything locally on the weekend. Looks like it's "Flying by the seat of the pants" time.
I found this searching around the net. Does it look any good? I don't want to get caught like this again.

#17 Post by **Kyocera** » Sun Jun 01, 2008 9:41 pm

As long as you have something to send a signal and something to receive and send a signal back your good to go. Worst case scenario you could use two thinkpads. One at the patch panel and one at the jack, plug till you get a link light on both machines.

ajkula66 · #18 Post by **ajkula66** » Sun Jun 01, 2008 10:12 pm

I've never used the test set in picture, but it should definitely perform the tasks that you need...

Good luck

#19 Post by **carbon_unit** » Mon Jun 02, 2008 5:42 am

I figure I will plug in one workstation, go to the "server closet" plug a cable in to the switch, and start hunting in the "patch bay" until I get a connect light. Then repeat for each workstation, marking them as I go. Maybe there will be some logic to how it is connected?

#20 Post by **Kyocera** » Mon Jun 02, 2008 7:27 am

Maybe there will be some logic to how it is connected?

hehe, don't count on it.

Just remember that if you think you have a valid connection on both ends you just might, but still not get any light, check the job they did punching down both the wall jack and the patch panel.

If you have a pc plugged into both ends, you can always use ping to make absolute sure you got the right port to the right jack.

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