[Gllug] Networks

[Zverina, David]

> Did you do the cabling yourselves? We've just been bitten by 
> exactly the same problem. With Cat5e, you not only need to 
> ensure the pinouts match on each end, but there is a 
> specified order for the wire colours. If you use the colours 
> in a different order, then obviosuly the cable is still 
> "correct", and passes a cable test. However, when you try and 
> send data down it over anything but a short distance, then 
> crosstalk between the individual wires means it won't work. 
> Much of last weekend was thus spent recrimping large amounts 
> of cabling to get the colours in the correct order. After 
> that, it worked fine...

It's not just cat 5[e] cable that is affected by this but all UTP cable
regardless of category. The reason is that each signal has to go down a
twisted pair so that inteference is cancelled out. Use wires in different
pairs and you've just made a whopping big 30m aerial. To make things simple
there is actually a standard (TIA 568A/B) [1] which specifies a valid (and
recommended order). However there are certainly other orders which will
work.

Cheers,

Dave.

[1] http://www.siriuscomputers.com/rj45.htm

This e-mail and any attachments may be confidential or legally privileged.
If you received this message in error or are not the intended recipient, you
should destroy the e-mail message and any attachments or copies, and you are
prohibited from retaining, distributing, disclosing or using any information
contained herein.  Please inform us of the erroneous delivery by return
e-mail.  Thank you for your co-operation. 
Mercer Human Resource Consulting Limited is regulated by the Financial
Services Authority and is a member of the General Insurance Standards
Council. Registered in England No. 984275. Registered Office: Telford House,
14 Tothill Street, London SW1H 9NB 


-- 
Gllug mailing list  -  Gllug at linux.co.uk
http://list.ftech.net/mailman/listinfo/gllug