Cat5 e cable problem

[octavee]

Hello,

I am stuck with this. We have a network with a D-Link router and 2 D-Link switches. So far so good. Now I connected the router with the next building (cable length 110 feet) with a CAT 5 e cable.
Option 1
I hook up a switch and the switch shows a green light. I hook up my laptop with a short cat5 cable. The sitch shows a green light. My laptop schows an orange light on the left and blinks short green on the right. It says network address assigning. And after it is assigned it indicates a 100 Mbit connection, but it does not work. Then I do the same thing with a desktop computer. No luck there.
Option 2
I connect the laptop direct to the cable instead of using the switch. Same thing. It does not work.
Option 3
I use a G4 (Mac laptop) direct. It does work.
Option 4
I use the G4 with option 1. It does not work, but the lights are green.
The cable is in a tunnel, 1 foot under ground for about 40 feet.

Any help is highly appreciated.

Thanks
Octavee

 

[wires]

I assume that a laptop connected with a short patch cable directly to the router port where the 110' cable would normally be connected works properly. If so there is obviously something wrong in the run to the next building.

Possibilities:

2. Connectors on cable are incorrectly installed, incorrect type or defective.

2. Cable is defective or incorrectly installed.

3. Interference.

The G4s network card is apparently more resistant to whatever signal abnormalities are happening so it is able to connect. My guess is that the G4s connection is not 100%.

 

[octavee]

What can I do to find a solution? Should I run another cable? How can I eliminate Interference?

Thanks
Octavee

 

[phuzzy42]

It's not clear whether there's a cabling problem or a communications choke-up. Is there a reason you're using a router between the buildings instead of just connecting the two switches together? The simpler the better - if you don't need the router, don't use it.

In "Option 1" you're connecting the laptop to the switch - that will provide a good connection between the switch and the laptop regardless of whether the switch itself can get out to the rest of the LAN.

In "Option 2" you connect the laptop directly to the cable. Do you still get the connect light (the solid orange on the left) and a signal light (the blinking green on the right)? If so, you're getting a connection as far as the router in the other building. Again, it doesn't mean the router is talking to the rest of the LAN.

Is the connection good between the router and the first switch? What happens if you connect the laptop directly to the router? What happens if you connect the cable directly to the first switch and bypass the router?

If your connections are good end-to-end, the problem has to be software such as mismatched IP addresses, the firewall in WinXP, or settings in the router and/or switch. To eliminate the cabling as the culprit, take the laptop and the second switch back to the first building and connect them directly there.

You didn't mention whether the underground cabling was sheathed for exterior use. In my experience, any conduit in the ground for very long usually gets water in it. If the cabling isn't exterior-rated, you may be getting breakdown and shorting.

You'll have to play Sherlock Holmes by eliminating the suspects one by one. I wouldn't go to the effort and trouble of replacing the cabling until I checked everything else first, starting from the first switch and working outward until the culprit reveals itself. The game is afoot!

Steve Harmon
Greenfield, Indiana

 

[octavee]

Hi Steve,

thanks alot for your reply. The router and the 2 switches are in building A and everything works fine there.
Now in building B, what is new, I have a switch what I use optional to figure out the problem. When I connect the laptop to the router or the switches in building A it works fine.
When I connect the laptop to the switch in building B it indicates it works, but it doesn't work. I can not ping out, I can not use the LAN. I tried hooking up to the router or to the switch in building A. The router is just for Internet (DI-624). There are no static IP adresses for the internet, cause it all gets hooked up through the router.

>>You didn't mention whether the underground cabling was sheathed for exterior use. In my experience, any conduit in the ground for very long usually gets water in it. If the cabling isn't exterior-rated, you may be getting breakdown and shorting.

The cable was just layed a couple of days ago. No rain. And the G4 laptop works fine and can connect to the LAN and the internet. Instead of the PC laptop I tried a PC desktop. But both PCs did not work.
I will go there now and try to move the switch as well to building A, hook up the laptop there.

Thanks so much
Dr. Watson

 

[skip555]

how are you terminating the cable that runs between buildings ?

proper termination would be cat5e jack on each end of the cable to patch cords to switchs .

if you have crimped a connector on each end of the cable and plugged it directly into the switchs it could be where your problem lies .

try terminating it with jacks and factory made patch cords

 

[octavee]

That might be the problem. I just moved the switch from building B to building a and it works fine. Do I have to terminate on both sides?

Thanks
Octavee

 

[octavee]

What kind of termination do I need?

Thanks
Octavee

 

[srmega41]

Try plugging your laptop directly into the CAT5 running from building A, out of the switch in A. Does it work without the switch? If so, you may just need to insert a rollover cable between the two switches. If the laptop works using the new cable, but the switch does not, a crossover is needed.

Hope this helps,

Scott M.

 

[phuzzy42]

Octavee, I posted a FAQ about straight-through and crossover cables (it may not be online yet) that may help. If you've put RJ45 connectors on both ends of the cable, I'd redo them before I did anything else - 90% of cabling problems are the terminations.

http://www.tek-tips.com/faqs.cfm?fid=6154

Steve Harmon
Greenfield, Indiana

 

[octavee]

Hello Steve,

can you give me some hints about the termination. The cables are straight through, so what do I have to look for? So far I never used cross-over cables, even when I connected a switch with a switch. I am not quite sure why to use a rollover or crossover cable?

Thanks
Octavee

 

[franklin97355]

You won't need them if your equipment is auto-sensing but if you had older equipment this would be necessary to communicate.

 

[skip555]

dont CRIMP a connector on the cable end its bad practice, not standards complinat and often problematic .

put a cat5e jack (not a crimped plug ) on each end of the cable , then use factory made patch cords .

 

[skip555]

90% of cabling problems are the terminations.

not if you properly terminate ie DONT CRIMP your own ends on , do it right to start and the numbers will be something like 2% of cabling problems are terminations

 

[franklin97355]

So where are your other 98% ?

 

[skip555]

So where are your other 98% ?

ok I should have said your cabling problems will drop by 98%

we do a lot of cabling and once we leave rarly do we have a legitmite cabling issue and almost never is it a connection .

had one yesterday where the cable was bad , looked like it was chewed by a rodent.

did have a bad port in a patch panel the other day where a customer had litterly hung a switch from the panel by a patch cord . bent the pins in the panel .

we do get a fair number of calls where someone had crimped either a cable or used a "scrap crap " site made patch cord .

 

[franklin97355]

Sorry, just couldn't resist. That's my take on things, use connectors, jacks and patch cables as they were designed and you will have few problems.

 

[phuzzy42]

Skip, the point I was making was that however the cables are terminated, it's almost always the terminations and not the cabling itself that are screwed up. I agree with you that a proper jack at both ends (or at least a 110 block) is much better than an RJ, but we're not in a perfect world and I've seen places where the IT staff just wasn't allowed to do the job right.

Octavee, the reason you might need to a crossover cable is that LAN equipment transmits data on one pair of wires and receives on another pair. Newer equipment can sense when you've got the transmit on one end connected to the transmit on the other, and will automatically swap its transmit and receive pairs so that transmit on one end goes to receive on the other, and vice versa. A lot of older equipment couldn't auto-sense, so data wouldn't flow over a straight-through cable, you had to use a cable that had the transmit and receive pairs swapped on one end.

In your terminations, your wire pairs should stay twisted as close to the termination as possible (you'd be amazed how much noise gets in if even 1/2 inch of wire is untwisted). If you're using jacks or a 110 block, make sure each wire is seated all the way in its groove and that you punch them securely. If you're using connectors (sorry Skip, gotta cover the bases), each wire needs to go all the way in to the end of the connector.

Rent or buy a tester and use it. A good tester costs thousands of dollars, but they can be rented. Even a relatively simple continuity tester can be bought for around $90 and it's better than nothing. It needs to be able to test for open pairs, crossed pairs, shorts, etc. Heck, you can even make a (very) simple continuity tester for around $15 with parts from Radio Shack.

Something else I haven't seen mentioned much is lightning protection. Any time a data or phone cable enters a building it needs a lightning protector. Phone protectors can't be used for data - you need protectors specifically designed for CAT. Protectors aren't cheap, but they're a lot cheaper than replacing all your computer hardware if lightning zaps you.

Obviously I can't go into an entire training course here - do a web search and you'll find lots more information.

Steve Harmon
Greenfield, Indiana

 

[octavee]

Hello all for the great information,

I have a switch that is autoensing, so the crossover idea is absolete. I will try today to make some progress on the project and report back either way.

Thanks
Octavee

 

[srmega41]

One thing that just occurred to me is what the issue is about crimping the cable. I have done this in the past and been successful, but the idea here is you can use a connector if you use the right one.

Someone correct me if I am wrong, but the issue here is solid core vs. stranded on the cable terminations. If you use a standard plug, they are built for stranded cable (i.e. Patch Cables). The prongs are designed to penatrate the cable, creating a connection within the stranded copper inside the insulation. A solid core cable is designed to be terminated on a jack, so the insulation is split and the copper connects to the metal on each side of the wire placement slot (I am sure there is a more technical term for this, but it escapes me right now).

Since the solid core is not designed for use with the plugs, you can get a plug that has a different type of pin. The ones I have seen have multiple teeth if you will, that are bent slightly to both sides, so when the termination is complete, the "teeth" penatrate the insulation and surround the solid copper core, instead of trying to go through it.

Sorry if I am stating the obvious, but I saw a lot of comments about not termianting the cable with RJ plugs, but not a real technical reason why. This may be what Steve was trying to avoid; but I wanted to verify my thoughts and throw some additional info out there, in case not everyone knew the reasons why or why not.

Scott M.