Patch Panel to HUB cabling problem!

[zoney29]

We have setup a 16 pc network utilizing a patch panel, HUB & cat5e cable. We have cabled to the patch panel and are using commercial patch cables from the panel to the HUB. Our problem is as follows:

We are not able to see any systems on the network other than the system we are on.

If we run directly to the HUB (bypassing the panel) we have no problem.

When we test the panel & cabling we get signals out of sequence [1,4,2,3]. When we test the HUB and patch cables our signal sequence is correct [1,2,3,4].

We noticed that the cabling codes are different on the panel [wb/b, wo/o, wg/g, wbr/br] and the patch cables [wo/o, wb/b, wg/g wbr/br]. Also .. the panel has a "180" designation .. does this mean that the cables need to be reversed to the HUB?

When using a patch panel to a HUB are there specific coding considerations that need to be addressed?

Thanks for any help .. this is making me crazy!

 

[MasterRacker]

Most wall jacks and hubs are colorcoded for BOTH 568A and 568B. Most comercial networking uses 568B. The difference is that pairs 2 and 3 are reversed between the two. Whichever standard you use, make sure you use the same one at both the wall jack and the patch panel. If you use 568A on one end and 568B on the other, you have a built-in crossover in your structured wiring. If you are buying premade cables and they are straight through, you can ignore the paring in the cables themselves.

We need more details on the configuration, because you only mention one patch panel.
Jeff
I haven't lost my mind - I know it's backed up on tape somewhere ....

 

[FredWagner]

Is the patch panel connected to wall jacks, or to another patch panel? It sounds like the patch panel was coded for 568A and the jacks for 568B, or vice versa. Had this happen when taking over an office once where they had removed their old patch panel, and we added our own, and came up with the same problem you have. You'll need to make the patch panel connection sedquence match the sequence of the jacks at the other end.

Fred Wagner
frwagne@ci.long-beach.ca.us

 

[MasterRacker]

Fred's saying the same thing I meant to say. "Most wall jacks and hubs " was supposed to read "Most wall jacks and patch panels". (I must not have been awake yet.... ;-) )
Jeff
I haven't lost my mind - I know it's backed up on tape somewhere ....

 

[ChrisAC]

For God's sake ... if you don't know how to terminate and test CAT5 then get someone in who does!! Either you know the wiring order or you don't!!

Sorry for the rant but I used to work for a cabling company and I've seen some right old sh*t on some sites!! Unless you get your cabling right then your network is for sh*t!! Get a contractor in to do your cabling then you know it will be right! If it isn't then you have someone to blame and put it right! Also, get test results! This doesn't mean just wiremap tests but NEXT, attenuation etc.. You should be able to get printed output from the tester (either Omniscanner, Fluke or similar).

Oddly enough the other day I went to our training room to drop off some routers and PC's and stuff for a training course and was looking for some data points. It had floor boxes in with the face plates loose under the lid. I lifted the face plates and turned them over to find the most awful termination job I've ever seen. The electricians had done the data cabling (LOL) and had stripped off about seven inches of the outer sheath and untwisted the cores!!

I give up!!

So, for your information, the correct sequence of colours for 568B is:

Pin 1 white/orange
Pin 2 orange
Pin 3 white green
Pin 4 blue
Pin 5 white/blue
Pin 6 green
Pin 7 white/brown
Pin 8 brown

Remeber that the odd numbers have the white in them and the even numbers use the solid colours.

For 568A the oranges are on 3 & 6 and the greens are on 1 & 2.

For a crossover cable wire one end as 568A and the other as 568B. Easy!!

Also, make sure that you keep the twists in the cable all the way up to the termination point.

Chris.
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Chris Andrew, CCNA
chrisac@gmx.co.uk
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