SOLVED - Re: [plug] home cat5 issues

Gavin Chester gavin.chester at
Thu Mar 20 11:21:08 WST 2008

On Wed, 2008-03-19 at 11:56 +0400, Brad Campbell wrote:
> Cat 5/5e/6..and so on is strictly point to point. The length
> limitations are to do with transmission 
> speed and reflections, and you will find that if you go from one end
> to the other it will work, but 
> any point in the middle won't. There is possibly a way you can do it
> which is to put 2 sockets at 
> each point and use a jumper cable between them, but any overhang will
> cause massive reflections and 
> horrible mismatches.
> X---X=X--X=X---X=X---X
> Where X is a socket, - is the structured cable and = is a jumper will
> work, but doing it the way you 
> are doing it will not ever be reliable even if you can get it to work.

Okay, all this exercise has done is prove the old maxim: a little bit of
knowledge is dangerous. I had thought I could apply my previous
knowledge and experience installing data and security cabling and create
a "multi-drop" wiring configuration for each cable length (interpose
connectors along length of cat5 to increase connection flexibility
rather than just end-to-end, ie, option of end-to-halfway). 

Brad's post finally hit the nub of my error and I got my unsuccessful
test cable to work via its mid-point keystone socket simply by chopping
off the 'dangling' end of cable that passed uselessly it to the end
connector. Voila! instant end-to-end connection instead of signal
bypassing the midway socket.

I've since done some more experimenting following his suggested topology
(above) and am connected as I type this via a test cable consisting of 4
segments arranged thus:

router <--------> ]------> ]------[  <----> PC

where "-" is cable, "<" is crimp end connector, and "]" is a keystone
socket. This proves that I can make my installation work with some
clever re-jigging as per Brad's suggestion and not having to rip out the
whole damn thing.

I've since done some reading and found that maximum number of segments
can run to 5 in total. I also found that the other cardinal sin I
committed in one part of my installation was to use 3-way telephone
cable connectors to create a "Y" in cable run. That'll have to go. 

Anyway, thanks to your help I'm a lot wiser and will now have to do the
best I can with minimal re-jigging of my laid cable and installed

PS: My problems all arose because of my ambitions to have the
flexibility of having 4 separate cables available for my 4-port router
in any room in teh house. This was so I could reposition the router
(changing the locus of the 'star') without destroying the network as
need changed due to renovations.


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