[AusNOG] Cable length limits?

[Paul Wallace]

The objective of the introduction of the higher spec cables have little to do with possible effects of heat.

The objective of the higher spec'd cable is an attempt to better deal with 'cross talk'.

Cross talk & impedance are the cable owners worst enemies, not heat.

Also, attenuation via tight loops & worse, pulling the cable into near right-angles, are basic mistakes that should be avoided.

After that there's a conversation about PoE over the same blue cable

'night!




From: AusNOG [mailto:ausnog-bounces at lists.ausnog.net] On Behalf Of Joshua D'Alton
Sent: Tuesday, 4 March 2014 9:05 PM
To: Paul Gear
Cc: AusNOG at lists.ausnog.net
Subject: Re: [AusNOG] Cable length limits?

Over 90m a change to say 40c would actually lengthen the cable by about 2%, so a couple meters, probably not a whole lot, but could be borderline. Most of the results should be from those trying to flog higher priced but same performing cables, nothing new there. If there were to be issues, it would be due to being so close to normal cat5e/6 limits, not temperature differences. As in, you shouldn't run it that close to spec in the first place.

On Tue, Mar 4, 2014 at 9:52 PM, Paul Gear <ausnog at libertysys.com.au<mailto:ausnog at libertysys.com.au>> wrote:
Hi all,

I'm working on a project involving a new facility being built in Townsville.  A consultant on the project mentioned to me today that he had heard some discussions which suggested that the maximum distance of 90m on a Cat5e/Cat6 run applies to environments where the ambient temperature is around 20 degrees, and that higher temperatures can actually require lower length limits.

Can anyone confirm or deny, and/or point to some relevant references?  Google seems to have some relevant hits, but discerning the wheat from the chaff is tricky - many of the first few hits for the searches I did were from companies trying to sell higher grade cabling.

Thanks in advance,
Paul

_______________________________________________
AusNOG mailing list
AusNOG at lists.ausnog.net<mailto:AusNOG at lists.ausnog.net>
http://lists.ausnog.net/mailman/listinfo/ausnog

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ausnog.net/pipermail/ausnog/attachments/20140304/00d0d576/attachment.html>