[Gllug] Networks

[Jim Bailey]

On Thu, Sep 12, 2002 at 11:07:20AM +0200, John Hearns wrote:
> On Thu, 2002-09-12 at 10:59, Peter Childs wrote:
> > 	We are trying to replace an old Bull DPS6 (15 years is old in computer terms 
> > is it not) With a linux based system using C++, Qt and postgres. The system 
> > controls hire cars travelling round London. If you want more details I will 
> > think about giving some. 
> > 	We are planning to connect our computers together using a 100Mbits Lan and 
> > switches around our offices in SE1. Maximum cable run is about 30 meters 
> > which is well below the 100meter limit. However when we try to run data over 
> > the links over 8 meters long we get no  data, we get a link (or at least the 
> > switch says there is one but no data travels) All the cable works fine at 
> > 10Mbits and the configuration seams to work on cables shorter than about 8 
> > metres.
> > 	The main problem we can see is that there might be problems with interference 
> > on our runs from UPS, Power (Non UPS), CCTV, Serial Cables (for the bull), 
> > phones (4 different types), etc. All the cable is in the same run under the 
> > floor.
> 
> Me, I would get in a specialist firm to help.
> And, hate to say it, maybe you should get costings from them to
> replace the cabling.
> A cabling firm will have test meters, and be able to give you printouts
> of the performance of each outlet.
>
John has got a point here if the cabling is old it may not be up to the
job.  Have you tried with new cabling cat5e?

> As you are in SE1 I remember dealing with a good firm, who
> had offices in Weston Street. But damned if I can remember the name...
>
Depending on the situation you might want to consider a general
electrical contractor for the cabling.  I have used them on numerous
occasions in past and athough they don't have the specialist expertise
of a dedicated cabling company, I have found them to be 25-30% cheaper.
A word of warning they do require more handling and you need in house
expertise to deal with unforseen problems, since they lack the knowledge
base to deal with unassisted with issues.

Peace Jim

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