[plug] home cat5 issues

[Gavin Chester]

On Wed, 2008-03-19 at 16:10 +0900, Mark J Gaynor wrote:
> I have not heard of a modified star topology, a star is a star. I would say
> that you
> have seriously changed the characteristics of the cable by placing sockets
> along
> its length. If the sockets were a normalized type (not come across cat5
> normalized
> sockets either) then I would say the idea would work. A normalized socket
> breaks
> the connection at the point of connection. I would say that stray capacity
> is your
> worse enemy here, resulting in a sad lack of speed.
> 
> Mark

I hadn't thought of stray capacitance from unused sockets :-/. I'd
thought an unused socket without breaking the cable would equal simple
stripped insulation :-/ That is, I was hoping that without physically
breaking the connection when I interpose a keystone socket that it would
be seen as one cable - potentially of varying length. 

Recall my previously discussed test cable of 30m with a keystone socket
interposed halfway along its length with crimped connectors each end.
Then I can elect to use it as a patch cable connected end to end - OR
substitute the halfway socket leaving the rest of the cable flapping in
the breeze. Sort of like quickly choosing between a 30m or 15m length of
patch cable when it actually still the same cable. Without breaking
continuity I thought this should work :-/. Another diagram would help,
perhaps:

SCENARIO 1/

X---------------O---------------X
|		|		|
PC				Router

One cable using end crimp connectors - this WORKS.

SCENARIO 2/

X---------------O---------------X
|		|		|
PC		Router

One cable using end crimp connector to midway keystone 
	- this does NOT work.

Got me stumped. And, yes I've triple checked the integrity and pinouts
of teh keystone - even temporarily changed it to T568B, instead of
T568A, just for the hell of it :-/

The next test I'm going to try to replicate my problem is to make a
patch cable with a "Y" connection so that I choose either of B or C
connected to A - not at same time, of course.

		Router
		A
		|
		|
		|
		|
	B------------------C
	|
	PC

Gavin  

> --
> 
> *********** REPLY SEPARATOR  ***********
> 
> On 19/03/2008 at 3:15 PM Gavin Chester wrote:
> 
> >On Wed, 2008-03-19 at 14:46 +0900, Hagar Horrible wrote:
> >> On Wed, 19 Mar 2008, Gavin Chester wrote:
> >-snip-
> >
> >> A simple diagram of my modified star
> >> > topology may help:
> >> > 
> >> > X-------O---------O------O------X
> >> > 	|			|
> >> > 	|			|	       
> >> > 	PC			Router
> >> > 
> >> > where each 'O' is a keystone socket and 'X' is crimped cable connector
> >> > on a single cat5e cable placed loose on the floor. All connections and
> >> > sockets test as good, but only X-X works, any combination of X-O or
> O-O
> >> > fails. WHY? Any ideas welcome. BTW: I have used two brand of keystone
> >> > socket, in case that crossed your mind.
> >
> >> 1) Are you using only 1 cable per computer?
> >
> >Yes, I have laid five parallel cat5e cables - one for each
> >PC/router/printer, but each cable is configured as above with multiple
> >drop offs to different points/rooms. Each will only serve one appliance
> >at a time - the extra drop-off points jsut give flexibility as to where
> >the appliance is placed on the cable.  
> >> 
> >> 2) What was the pin/color combination for each plug?
> >
> >Done to T568A specs.
> >
> >> 3) was the cable single core ( for fixed wireing )
> >> or twisted (core for more mobile solutions)?
> >
> >Single core cat5e
> >
> >> 4) is your router a hub or a switch and what
> >> about the nic in the computers ?
> >
> >Important questions, but I don't think relevant to my issue which
> >revolves around connecting to keystone sockets as opposed to crimp
> >end-connectors. See other follow up post for info.
> >
> >gavin
> >
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