Net work Cabling Puzzler

OK, Here's one for you network wiring gurus:

Have DSl modem, router and Hub
Plug dsl modem in get signal hook up to computer IT WORKS

Next step, check out uplink to multi port hub use straight thru cable switch hub to straight thru no go swithc to crossover, voila it works...!!!
All ready for Whole house wiring....the fun starts
Wire up various rooms 568B style. Did a check caus Im not using a path panel at the hmodem/router/hub site (just plugs)

Test wire works good (basically a plug wired into a leviton 568 jack with 568B configuration. Wiring scheme seems sound. Run wires cut jacks into walls all is good...
Plug in first network connection....Houston, we have a problem... blinking connection light on hub, no network detected on computer end....recheck wiring and all seems ok, cut off plug and rewire check continuity OK still no go...

Hmmmmmmm Any Ideas? Probablysomething so stupid but I am new to netwoks and wiring and want a whole house network...

Please don't say go wireless, I live in the vicinity of Mt Sutro with the largest antenna and it wipes out all radio transmission (even car alarms don't work up here!)

You won't regret buying a patch panel, but it is definitly possible to get it to work the way you're doing it. I've used both methods... Really you just need to sit down and make sure you've got everything going strait through from one connection to the other... You can look at your jack and see where those wires lead, then make sure you're crimping the ends on in the same pattern. Check to make sure you havn't flipped the end over when you're crimping it on... Try out your wiring scheme by making a short "extension cable" that's only a few feet long, as it'll be easier to debug, and give you something to take along with you as you punch down jacks and crimp ends...

Matthew

How long is the cable you are running? Are you sure you're using the correct pairs? (1-2, 3-6) If you know this, don't mean to insult, but the live wires need to be twisted on semi-long runs. While this SHOULD still work, It could cause your nic to stop transmitting if it sees too many errors.

Oh, and the only crossover you'd need is from the hub to the DSL router, assuming you have the Xover turned off.

Well That explains the need for the crossover switch to be turned on on the hub, I had a straight thru cable connecting thought that the straight thru setting would work that was a lucky fix..

I did the short cable thing to make sure I was not doing the wrong thing and the short hookup worked great. the longest run is no more than 100ft so that shouldn't be an issue. I'll check everything again but I could not have wired 6 connections wrong and they all end up with a blinking activity/link light as opposed to a no light which would mean dead

GRRRRRRRR

Had exactly this problem before, using a crappy quality cable. The run was barely 10 meters, but it was one of those 'flat' network cables. Plugged it into the computer, and the light on the hub flashed on and off about once every second. The WinXP connection status thing also kept coming and going about as often (although it couldn't keep up).

Fixed this temporarily by reducing the connection speed to 10mbps half duplex in the network card settings, and permanently by buying some decent quality network cable.

HTH,

A.

I don't know if they made it clear enough in the earlier posts in this thread, but...

When wiring category-5 network cable, it's not enough just for Pin1 to go to Pin1, Pin2 to go to Pin2, etc.

The wires are in special sets of twisted pairs. Certain pairs of the wires must be twisted with each other in order to prevent inductive noise and RF interference from killing your network connection. So you have to be sure to run genuine category 5 cable, and the wires have to be punched into the network block in the correct color-coded order, or else the run will fail (or at least be intermittent). The longer the run, the more likely this is to happen. A two-foot cable run with the wrong pattern of pairs might work fine, but extend that to 100 feet and you're scrod.

So. If all you're paying attention to is whether or not the source and destination pins come out right, but not paying attention to the actual wire pair order in the run itself, then that could possibly be the problem.

In the past, someone has posted a graphic of the correct Cat-5 pairings here on the BBS. Anyone have that link?

This isn't the one posted before, but it looks about right:

http://www.avontech.co.uk/advice/cat5.htm

Just so you understand what's happening, and why it's important:

Twisted pair cable is designed so that interference is self-canceling on the cable. This is accomplished by the twists in the cable. Since Ethernet only uses 4 out of the 8 wires, you only need 2 pairs. Forthermore, it was designed by someone in the military, so the design is a little f'ed up. instead of using pins 1,2,3,4 like a normal human being, they decided to go with 1,2,3,6 leaving 4 and 5 in between the active pins. Basically, you rather pointed to (what I believe is) the problem with your earlier post. If you use the wrong pairs, two of your wires are no longer twisted, and therefore, no longer shielded at all, so you have 2 100' antenna's on each of your network cards. Since you live in a high emf area (Enough to kill wireless) This would be exceedingly important to your setup.

Let us know how it turns out, I'm curious now.

Thanks Tony,
I actually took the time to look up the proper cabling technique (three twist per inch no mor than 1/3" untwisted and asked our wiring guru at work to critic my "Sample patch" Jack- to-plug scheme and he said I was a bit OCD on the twist (overkill) but that it looked fine (wanted to hire me!). I'm gonna borrow the $5K network connection tester today and really see whatup tonight. The cable is Cat 6 (marketing ploy?) certified and exactly what we use here at the office (400+ Computers so that shouldnt be the issue....Hopefully some solutions tonight, at least more info

Anyone know why there are two standards? I had heard that A was used to tie in legacy systems and is not used much commercially any more. We use B at work so I gravitated to that at home....

I'm gonna borrow the $5K network connection tester today and really see whatup tonight.

Good call. That'll tell you what's up for sure.

Ooooh network certifiers are fun to play with... It makes running cable so much less exciting, as you know if it's good or not the moment you punch it down. Cat6 is a marketing ploy, all right... Last time i was in my favorite local electronics shop, the owner was on the phone and told someone what they wanted didn't exist, then offered to go check and make sure because "Cat 6 doesn't exist, but we've got it".

Matthew

Last I heard, Cat6 was a proposed standard, but was still a good ways away from being ratified. Any Cat6 cabling should approximate that standard, but since it's still in a state of flux ... well, who knows?

Network tester to the rescue...A word of advice strip all of the outer jackets by hand with extreme care...turns out the conductors were nicked and ended up breaking INSIDE the insulation (insulation holding them together) this ledt to open (ie broken connections) in half of my connections. netwok testers are the way to go even the 49.00 versions work well for this.

Connectors re-punched down, plugs set, ready to tackle the vaugarities (sp?) of network admin and (network gods willing) Whole house networked empeg!!!! YEEEEHAAAA

Congratulations! Glad to hear it all worked out.

Get enough of that network experience under your belt and you can do it for a living.

That's why I always try to get the cabling that has the harder plastic ``insulation'' (usually plenum cabling). In my experience, you can just score the plastic and bend it and it'll snap off, kind of like how cutting glass works. This way, you don't run the risk of what you just described. Of course, it usually costs quite a bit more, but it's real cheap when you just use the leftover spools for the stuff you bought for work.

I also like to use solid cable instead of stranded cable becuse it's so much easier to work with. And how often am I really going to move those cables anyway?

Oh -- and make sure you use connectors (that is, the actual plastic RJ-45 ends or heads) appropriate to the type of wire in your cable. Solid wire connectors are different from stranded wire connectors. There are some that do double-duty though. Even better, they're often unlabelled (or you've stored them without labelling them), so you need to learn to recognize them by their physical features. Solid wire connectors will have the spikes that dig into the wire offset from each other, so that they can wrap around the solid core. Stranded wire connectors will have spikes that just point straight down into the wire, embedding themselves. The double-duty ones usually have three spikes, one on the left, one in the middle, and one on the right, working like a bastard, combined version of the other two.

Anyone else have any thoughts or tips on network cabling?

In reply to:

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Anyone else have any thoughts or tips on network cabling?

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Oh yeah, plenty :-) First off, buying plenum just because you like working with it is pretty insane... Plenum is actually used because it doesn't produce toxic fumes when it burns. If you're doing a real job that has to be Up To Code, check and see if you need to use plenum.

If you're running wire *anywhere*, buy two boxes, and run two wires. Wire is cheap, time is expensive. You'll never regret having a seccond run ready to be punched down or plugged in at a moments notice.

Years ago I helped network my high school, our motto was (except in latin) "it is better to as for forgivness than permission". It got the job done...

If you have more than one computer at home and don't have them networked, you really should take a weekend and do it...

Matthew

First off, buying plenum just because you like working with it is pretty insane... Plenum is actually used because it doesn't produce toxic fumes when it burns.

...

Wire is cheap, time is expensive.

But I've never cut a wire when using plenum wiring, and have never had to redo a run or connection because of it. Given that time is expensive, that tends to, IMHO, offset the additional cost of the wire.

And I don't know that that hard insulation is necessarily specific to plenum wiring. It probably is, though. Teflon, I think.

They are the two standard ways of wiring the RJ45 connector. If you use one of each, you have a crossover cable. Using one or the other does not really matter, just make sure you are consistent.