OT: cat 5 cable, ethernet, connection jacks

[Henry Spencer]

On Thu, 24 Mar 2005, Madison Kelly wrote:
>    Well, strictly, no you can't. Realistically though, if you are in a 
> pinch, you can run two runs through one RJ45 cable but you will probably 
> have trouble with cross talk...

Good point, I'd forgotten that.  At the original Ethernet speed of
10Mbit/s, using wires 1+2/3+6 for one line and 4+5/7+8 for the other
actually works quite nicely -- I know people who run that way in
production.  No, there's no crosstalk problem, not at 10Mbit/s anyway.

At 100Mbit/s I would expect trouble.  Although if distances are short and
signals strong, you can get away with many things that wouldn't work in
the worst case. 

This doesn't get away from the inherently point-to-point nature of the
wiring, mind you -- it just exploits the fact that the standard cable
has twice as many wires as it needs and so can hold two connections.
It doesn't generalize to three or more.

                                                          Henry Spencer
                                                       henry-lqW1N6Cllo0sV2N9l4h3zg at public.gmane.org

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