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Network Wiring Problem - HELP!
TooEarly Sep-05-01 11:18 AM
I've been wiring Cat5 for the past year for LANning purposes for myself and many friends. But I ran into a bizarre situation. Right now i'm using LG UTP Cat5 wires.

I recently ran a 200 Feet cable and tested it with a FoxandHound Tester (which only test to insure that each wire is working properly... in case of shorts). And that Wire tested perfectly except when I plug it in from the router to the NIC it would not work even with a reboot and all! I know its not the Computer cause i moved it closer to the hub with a shorter cable and it worked fine! Maybe it was the cable so I ran another 200ft, and that tested fine! But that cable too did not work. I know the cables are fine because the tester said so. But just to be sure I used that same 200Ft cable from the Modem to the Router and it worked fine! I have followed all the cabling rules so what could possibly be wrong?

More details:
1.)These are extremly long patch cords (meaning that its ONE whole cable from the hub/router to the computer... No wall terminals)!

Question : Do wall terminals actually help or is it only for presentation?

2.)Instead of making cables like the 568A/B style I just ran each twisted pair next to each other, and having the identical image at the other end! Remeber that these Cables have been tested and they do work!

Question : Is it because I did not follow the 568A/B diagram that I maybe having crosstalk on the cable, thus preventing my cable to work? (i've been doing this for awhile and all my shorter cables work!)

Conclusion : I got the computer to work BUT only in Half Duplex Mode (which is very slow)... If I set it on AUTO or 100TX It would not work!

Question : What is creating this problem? I thought if I stuck within the Cabling rules, all I would have to do is plug it in and go! Is there more exceptions to these rules? I just would like to know the cause of the problem so that in the future I may be able to prevent it... Even though I did fix my connection problem I would like to run at FULL DUPLEX! So what can i do so that computer can run at full? Thank you for your time!

TooEarly


3. RE: Network Wiring Problem - HELP!
lbyard Sep-05-01 03:45 PM
In response to message 0
>Question : Do wall terminals actually
>help or is it only
>for presentation?

No, in fact they degrade the cable a little. See http://duxcw.com/digest/Howto/network/cable/cable2.htm for more info on the type of cable. Use solid core wire for cables that long. Be sure you have CAT 5 RJ-45 plugs designed for solid core wire.

>2.)Instead of making cables like the
>568A/B style I just ran
>each twisted pair next to
>each other, and having the
>identical image at the other
>end!

This is the likely cause of your problem.

>Question : Is it because I
>did not follow the 568A/B
>diagram that I maybe having
>crosstalk on the cable, thus
>preventing my cable to work?

Yes.

>Conclusion : I got the computer
>to work BUT only in
>Half Duplex Mode..

>Question : What is creating this
>problem?

One set of pins is connected by wires from the same twisted pair and the other set is not. One set works and the other set does not. Larry

Q. Does the order of the colors of the wires in a straight-thru twisted-pair network cable matter as long as both ends are the cable are wired the same?

A. You can use either standard color code, or invent you own, if desired. I use the 568A color code and it is the “preferred standard.” The colors do not matter, but the choice of wires does. Simply making both ends the same is not sufficient. The Ethernet interface uses four of the eight pins in an RJ-45 plug. Each end of an Ethernet cable connects to a transmitter and a receiver. A transmitter uses two pins and a receiver uses two pins. The two pins (+ and -) on the transmitter have to be connected to the corresponding pins (+ and -) of the receiver at the other end by wires in the SAME twisted pair and vice versa. A transmitter is not connected to a receiver by one wire from one pair and a second wire from a DIFFERENT pair. As the pins that are used, 1, 2, 3, and 6, are not sequential, one cannot simply match ends in a convenient manner and properly connect a transmitter to a receiver with wires from the SAME twisted pair. If this description seems a bit complicated or fuzzy, pictures can be found at http://duxcw.com/digest/Howto/network/cable/cable5.htm.


4. RE: Network Wiring Problem - HELP!
TooEarly Sep-05-01 11:01 PM
In response to message 3
That helps soooo much. Thank you very much... I will go try that right now to see if this will solve my problem. I'm sure it will... thank you for the prompt response!

TE


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