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I am involved with demo'ing an old office area and it is plumb full of cat5 data lines that are currently connected to their router or hub (T10/100?) if the data lines are cut prior disconnecting them from their hub, would that pose and danger to the hub? it seams to be not a problem but I am not certain, data lines are not my field of expertise. Any info would be helpful. Thanx

P.S. the hub is not accessible and will not be for a while hence the question otherwise the project could be delayed and I am trying to avoid that.

Merely cutting them will not hurt anything but the loose wires swinging in the air might. The possibility of ESD damage is significant and contacting energized conductors is sudden death.
Just unplug everything before you start.

It shouldn't cause any problems, but make sure that you coordinate with the IT people and get them to sign off on it.
In my experience, there are a whole lot of IT "experts" who don't really know diddly and will blame you for anything that goes wrong with their network or their equipment.

I had one give me a tongue-lashing for messing up their server by my touching a wire. He shut up quick when I showed him that the wire was a scrap left over from some renovation work done months earlier and was never connected to anything.

Remember that many of these folks are the ones who "fix" their problems by cutting the ground pin off of the plugs.

Delay!?

So be it,have Them 'IT' make safe your demo.

Other wise..your delay is a big loss of revenue (for you). and a new system for them (at your expense).

Just my little thought. or...DENY,DENY,DENY !!!!! (sometimes that works).

Can't you just insist that you be afforded the opportunity to tone out the affected cables, disconnect them and not run the risk?

Yes you do run a risk of damaging things if the existing switch (hub) is equipped for POE.

I'm no fan of CGs (computer geeks) either, but you need to demand to have access to the switch to afford you to make the disconnection. Rest assured that if you don't, when the IT guy's car won't start a month from now, it will be your fault.

Now this is OT:
My friend who owns a gas station.
Did a state inspection on a vehicle (passed),they came back a week later claiming their rear power window was damaged (not working)due to something they did during the inspection. (people are 'funny')

Back on topic: Trust no one. It will most assuredly take longer to be careful, then to just have them (IT) give the green light. Let them know of the potential,they will respond.

Cut them and then wrap the ends in electrical tape to prevent them from contacting anything that might damage the hub.

I think Ethernet hubs are pretty resistant to ESD, but you could wear a ground strap while you're cutting them if you're worried.

If it is Cat 5, disconnect at the cross-connect panel, then cut them.

yes, but what if the wires touch each other, that may become an issue

If the conductors in each cable touch one another, the system SHOULD read that as a shorted cable and ignore it.
BUT, you should know that you stand a very good chance of being put in the trick bag if anything ever goes wrong with their IT system. Write down exactly how you are going to deal with your end of the cables and officially hand it to them so they can't later say that hey had no knowledge of what you were up to.
As I said before, I fervently believe that the majority of IT folks are clueless and are just itching for a chance to blame someone else for their system woes.

I had one of our IT staff try to fix a computer problem last week; and a lot of her time was spent opening various windows muttering, "What's this one do? Let's try this setting. Let's 'google' it and see if anyone else knows how to fix this." ... followed by "I'm going to get him a better program, this Microsoft program isn't the best" when there are only a few of us in a thousand user network with this issue. If it was a bad piece of software, wouldn't it be acting the same on ALL of the machines throughout the company?
If we go out on a call and there's no power on the load side of a transformer how many of us would install a new Service at a different voltage? I dare say that we would at least try to find the blown fuse or failed transformer before we ripped out the whole electrical system and replaced it with a something different.

Keep in mind, these people invented the concept of "reboot". Their first instinct to a problem is to turn it off and on and see if the problem goes away...their second instinct is to blame someone else.

The hub or switch is designed to deal with that problem. If the transmit pair somehow managed to get shorted to the receive pair (that's two specific sets of wires that would need to make contact), the hub or switch would just disable the port until the problem went away. Any other pairs getting shorted simply wouldn't do anything.

Some of the IT people I deal with are "ping monkeys". They know how to ping things and that's it.

I understand the switch or the software should be able to disable this port in the software but 100' of unterminated cable (times how many you cut) could put a huge ESD spike into the system if lightning hits something a block away.

I do agree nobody really fixes anything anymore in the computer business but I figured that out in the late 80s and started doing other things

It's all about time & money; management doesn't want their techs to spend their entire day troubleshooting a problem with Word, when the system could be wiped (via network ghosting/reimaging) and the problem is guaranteed to be fixed after a 30-45 minute download process.

The problem arises when it was really a hardware issue and the download didn't fix anything. So they reload the system, still no joy. Now they have lost a day or two's data (how good was your backup strategy), a lot of down hours and they still have to send someone to figure out what the real problem was.
The industry has lost the whole concept of basic problem analysis. They run a script and shotgun possible solutions until something works. Unfortunately sometimes the cure is worse than the disease.

A problem with Word isn't likely to be hardware-related; if there are problems with the core OS and having everything restored doesn't fix it, then we pull the unit and do hardware tests. Hardware problems are pretty rare (aside from keyboards & mice), but when they do they are most often dead hard drives and the occasional power supply.

Nobody SHOULD be storing anything of importance on their local hard drives; other than their iTunes libraries, we tell everyone to store their files on the network. Not only is networked storage on a RAID-5 array, it is backed up off-site every night, and it is access-controlled, whereas anyone can access C:.

Of course, I can only speak for our department and organization.

LOL,
Welcome to the results of short-form IT courses.

I know hard drives are #1 on the hit parade but a bad memory stick can cause strange problems that might only show up on one program and not even be a solid bug.
I had one that only failed when you were burning a DVD.

You seem to have excellent data management there. Your shop is rare.

Unsure how this is different from the common situation of a hub/switch connected to in-wall building wiring that has no PC connected to the other end. Not every drop is used on every installation, some never get used, some are only used occasionally, etc.

I view it as a result of the continued dumbing down of America.

Maybe the world has changed but when I learned this stuff in the 90s, you didn't plug the head end in until you had a terminal on the other end with UTP.
That was why IBM sold an STP solution.
They don't sell much of it these days so maybe it was BS

Sounds like BS to me, or it could have only been applicable to Token-Ring (which practically nobody uses anymore). I have never used or worked with Token-Ring so I can't say for sure.

Token ring, at least in the IBM implementation, used a shorting type plug and receptacle that closed the ring when it was unplugged.
I tend to agree a UTP in a punched down keystone is safe but just having the bare wires swinging in the air still sounds like it is open to causing problems.

There was a way to run Token Ring over UTP, I believe you used adapters called media filters to do it.

Bare wires swinging in the air could be a problem..why I suggested taping them off.

Not sure about sending Token Ring over UTP, but we did the opposite in the old building (temp solution before it was torn down and rebuilt), using the old Token Ring wiring and a homemade adapter to connect computers to an Ethernet network.

State Farm ran T/R on Cat5. Yes they do call that balun a media filter.

It might be useful to check and see if they run Power Over Ethernet.

Just make sure you CYA, because some of the switches in the server room could be upwards of $40k to $60k And like others have said, watch out for PoE

~Matt

Most switches will isolate any shorted or open lines, even PoE switches a current limited and will isolate a shorted line. Some of the older Hubs did not like shorts and would slow down the other ports. I always contact IT before doing anything with their stuff. Although I have IT certification, most IT guys are real protective of there territory and will blame any one else on any failures their system has. Robert

Since I'm one of those 'geeks' (actually a network analyst in a large health authority) and there doesn't seem to be a great respect for my type here, I'll keep this short.

If you absolutely KNOW it's a (non-powered) hub and you know the difference, you're probably just fine. However, if any of those wires is connected to a switch or router, especially one that provides PoE (power over ethernet), you could cause all kinds of trouble. We get automated alerts every time someone does something that "shouldn't be a problem" with our network....

BTW, check out the replacement prices for a new Cisco PoE switch sometime. If that doesn't make you careful, nothing will!

Welcome to the forum YES we need all the geek help we can get, at least i do,fortunately i also know someone in IT for a major health region,plus guys in telco, radio comms, and IT on large campus's

Fortunately I am on their irc channel and can get help faster than having to call offshore

All current PoE switches are current limited. a short or open or overload will kill the power to that port with no effect on the others. If you connect non PoE equipment to a PoE port no power will be applied. Older PoE switches and equipment built before the PoE standards were released, may or may not be damaged by shorts.