Patch Panel Termination

sorry...pictures are here.

Thanks Robert....thats' the response I was hoping to hear....I really didnt want to have to rerun all the cables....but if it were the cause of my issue, I would without hesitation.

Brad

Still I would call up that electrical conmtractor and tell them to do the job right. Stripping the claddding away like is wrong. Its an extra layer of protection, and them taking it off is pretty dumb in my opinion. god only knows how their electrical installation was done????

Joe Perkowski

Unlikely. Although jackets should not be that stripped, I haven't heard of it causing trouble so long as the pairs are kept twisted.

I would expect to see CRC errors from bad cabling. You can test with `ttcp`. There may be some software issue, like an overloaded DNS or NetBIOS running.

-- Robert

Oh, you should bring someone in with a certification scanner long before doing anything as tough as recabling everything.

-- Robert

Actually...God isnt the only one who knows....I know....and found out the hard way. We have a standardized cublice structure of about 5-7 workstations in a cubicle area. He set up 2-3 cubicles (15-21 machines) on a single circuit. Its a joke. The problem is that it has been almost a year since we moved to this building....(I identifed the potential cabling issues 2nd day I was there) and management has yet to act on it. I am almost sure it is too late.

BTW. I have access to a Fluke DSP 4000 to certify cable and an Optiview II and every one I tested passed fine.

Actually, stripping back the sheath is common in telecom work. If the wiring is fairly dense, the sheath takes up a lot of space. On some of the systems I've worked on there were 224 pairs terminated on a panel. You simply don't have room for sheaths in that sort of install.

Ya I know, but, Im talking about is 24 port patch panels...I never known installers to do that on panels like that.

But, as the pictures illustrate, so long as the twists are maintained, the jacket, in this case not insulated should have little effect being absent?

Understood...I still wouldnt do a job like that....I think anyone who leaves a panel like needs to have their heads examined...There is a reason why cable manufacturers put cladding on the pairs you know!

Yes, the missing jacket will defiantly have some kind of a effect on cable performance. Will it be enough to cause Ethernet performance? Maybe not. But will it effect Cat5e performance, absolutely. If the components in this install are Cat5e, I would expect these cables to fail the test.

The jacket is unshielded twisted pair wiring surrounding the wire pairs is mostly just a mechanical protection. The outer jacket protects the insulation of the individual pairs form mechanical damage that cna happen when pulling cable to it's place and when cable is is installed. The outer jacket also keeps the pairs mechanically ordered in the way they should (nicely evenly grouped together).

The outer jacket has early no effect on the signal traveling on the cable! If you have just the original wire pairs from the cable, just as tightly together as they ar enormally on the cable, without the outer jackets, cable will perform still well for the signals traveling though it. No problems. It might be even hard to measure the difference between cable that has outer jacket or not.

When talking about single cable away from other cables, it should not matter much is the cable jacketed or not for the signals traveing through it! When you pack more cables together, the outer jackets keep some separation between the pairs form different cables, thus giving better isolation between the cables than just putting all the wire pairs from different cables tightly together. Other thing the jacket adds an extra electrical insulation layer. There is somewhat limited voltage that the cable can withstand between the wires on the pairs and between pairs. When the cable has this insulating outer jacket, the cable can withstand more voltage between individual pairs and outside of the cable than between the individual wires inside the cable.

Things are somwehat different when talking about shielded cables (those that have braid/foil shield on the jacket). But for unshielded cables, the outer jacket is mainly just mechanical protection (agains mecanical damage and to keep pairs arranged) and extra insulation layer!

Removing the outer jacket does not cause problems to Ethernet performance as long as you keep the wire pairs arranged together as they were with the jacket. And you don't put the wire pairs from different cables too near to each other (for example keep some mechanical separation instead of jackets).

If you put the wire pairs from different cables without outer jackets together, then the performance of the cable to cable crosstalk is poorer (more crosstalk) than with the installtion where outer jackets are in place. This can have effect or not for the system performance. This depends on how close to the perfomance limits the wiring already was.

I think that doing the installation where the jackets were removed for few centimeters distance and all wire pairs packed togehter as shown on earlier posted link, the individual cables might well pass the CAT5e performance tests when tested individually (if not anymore CAT5e, then most propably still CAT5). The perfomance when measuring single cable should have not changed radically if no considerable mecahnical damage is not done (wire pairs from one cable keep grouped/teisted together as they were inside jackets, the cable fasteners not overtightened etc..). The only neasurement where I would expect noticeable change is cable to cable crosstalk figures. Those are poorer than with the installation that keeps the jackets on the wire pairs as close to the terminating point as possible.

I don't doubt that the cables shown in the pictures would pass Cat5. I've tested some very sketchy cables and they passed Cat5. But that's another story. Yes, crosstalk is definatly where I have seen problems with this type of install. And in the real world you're not going to see a single cable install. Also, this single point would probably not be enough to fail a Cat5e certification, but seeing this type of install would make me question the rest of the installation and make me wonder at what other point may there issues. So the cumulative effect would be a failed link.

Without using the right tool, by the looks of things.

And the cable ties are not too tight. Which is another reason for leaving the jackets on.