[tech] CAT5 on patch port 8 to hub

[Simon Fryer]

Bingle

> A while ago Duncan Sargeant tapped:

> Trent Lloyd wrote on Sat July 27, at 16:47 +0800:
> > I just recripmed the small patch cable going from patch-8 into port
> > 8 on the hub.  It had a break somewhere and was working dodgily,
> > works all good now
> > 
> > The wire order isnt standard but that wasnt my fault, the other end
> > was weird so i just matched it ;p
> 
> That's to be expected :-)  When we wired up the UCC with cat5, we didn't
> bother with any order, just crimped one end and then made sure the other
> matched it.

Bzzt. We did bother. All the krone termination blocks we used have the 
appropriate wire colours labled on the back. This made wiring up the 
blocks incorrectly (and have them work) more trouble that it is would have 
been worth. 

[MTL] went a long way to try and work out which standard should be used
for the colours on the patch cables. The document showing how to wire up
patch cables correctly was on the notice board for a long time. I am not 
sure where it is now. Maybe [MTL] can provide a URL or something to the 
document. 

Other unknown and little implemented standards at UCC include the following:
* Certain cables with RJ45's where initially built for axalotle. These will 
  definatly look wrong. 
* Cross over cables typically have a red marking (cable tie or something)
  to indicate this. 
* A number of cables exist that where used to try out token ring. These will 
  also look wrong. 
* UCC typically buys the really cheap RJ45's and these don't often crimp 
  reliably. I found an ISA slot cover and a hammer a reliable solution 
  to fix this problem. 
* People at UCC tend to be lazy setting equipment up. This leads to a 
  number of badly crimped patch cables leading to all sorts of problems. 

Simon

-- 
------------------------------------------------------------------------
"Well, an engineer is not concerned with the truth; that is left to 
philosophers and theologians: the prime concern of an engineer is 
the utility of the final product."  
Lectures on the Electrical Properties of Materials, L.Solymar, D.Walsh