[ale] cat5

[Geoffrey]

Denny Chambers wrote:

> This sounds like a bad idea to me. You may actually get it to work, but
> I would think it would only work on shorter cables. On longer cables I
> would think that the signals would degrade allot faster, especially if
> both sets of pairs were carrying allot of signals. Using twice as many
> cables is not uncommon in computer cables. Differential SCSI use twisted
> pairs to extend the effective length of the cable.


Understood, but then again, it's just an experiment.  Point is, it's a 
rare occasion when both computers are on, much less using the network. 
One is my wife's and she uses it for school, mostly weekdays, in the 
evenings after my daughter has gone to bed.  The other is my daughter's 
and she uses it mostly on weekends and early evenings.

What I plan to do is fire them both up and try to saturate the network 
from both machines at the same time.  Then I can see if there's degradation.


I guess I could go out and buy another $29 hub and save me all the 
trouble, but that's not what it's all about.  Enquiring minds want to know!


> 
> 
> Geoffrey wrote:
> 
>>Well,  I assume you're probably on the right track there.  From that
>>point, you might asssume that if you used the other 2 pairs in the same
>>way as the first 2 are used, you'd be okay.  But then you'd probably
>>have to deal with cross-talk/interference between the two different sets
>>you've not, not just between rec/transmit on one 'communication link.'
>>
>>I think I'll give this a spin just the same and see what happens.
>>
>>Since one twisted pair is used for transmit, the other for receive, I'll
>>see what happens if I use the other two pairs in the same way.
>>
>>Joseph A Knapka wrote:
>>
>>
>>>Geoffrey wrote:
>>>
>>>
>>>>So I said all that to get to this.  Assuming you're only using half the
>>>>wires in said cable, if you use the other half for another connection,
>>>>is this going to cause problems (interferance)?
>>>>
>>>>
>>>Apparently yes, cf Mr. Glass's message. I now recall that two
>>>wires lying side-by-side basically form a giant capacitor, which
>>>means signal degradation. When you twist the wires together, the
>>>capacitance problem goes away. So the eight wires in Cat5 cable
>>>form 4 twisted pairs, and you probably do need to wire them in the
>>>proper order so that the twisted-pairs work out right. But I
>>>have totally exhausted my feeble knowledge of this matter, so
>>>don't take my word for anything...
>>>
>>>Cheers,
>>>
>>>-- Joe
>>>"I should like to close this book by sticking out any part of my neck
>>> which is not yet exposed, and making a few predictions about how the
>>> problem of quantum gravity will in the end be solved."
>>> --- Physicist Lee Smolin, "Three Roads to Quantum Gravity"
>>>
>>>
>>>
>>>
>>--
>>--
>>Until later: Geoffrey           esoteric at 3times25.net
>>
>>"...the system (Microsoft passport) carries significant risks to users that
>>are not made adequately clear in the technical documentation available."
>>- David P. Kormann and Aviel D. Rubin, AT&T Labs - Research
>>- http://www.avirubin.com/passport.html
>>
>>---
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>>
> 


-- 
--
Until later: Geoffrey		esoteric at 3times25.net

"...the system (Microsoft passport) carries significant risks to users that
are not made adequately clear in the technical documentation available."
- David P. Kormann and Aviel D. Rubin, AT&T Labs - Research
- http://www.avirubin.com/passport.html


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