Tom Hula wrote:

> I have my cables wired the same as the patch cables (as far as I can
> tell): orange/white, orange, blue/white, blue, green/white, green,
> brown/white, brown.
>
> Meanwhile, he tells me that I should have my straight-thru cables
> wired: green/white, green orange/white, blue, blue/white, orange,
> brown/white, brown.

He is correct for EIA/TIA 568A standard Category 5 cable.  568B swaps
green and orange.  Blue and brown are consistent with both.  Pinout-wise
both 10Mb and 100Mb only use 1-2 and 3-6 (green and orange in your
example).  4-5 and 7-8 are typically unused, though in some instances
they can be used to "squeeze" two links over one cable (with suitable
wiring accomodations on either end), but not recommended as the coming
Gigabit over copper standard requires all 4 pairs and you will have to
redo your cable infrastructure.

> There is something funny, since I sent for a replacement switch and it
> exhibits the same useless behavior. I hate to think I have it set up
> all wrong, but then I have been wrong a few times.

Correct your cabling.  As long as the ends are wired the same (which you
did do) and the *pairs* are wired correctly (1-2, 3-6, 4-5, 7-8) the
colors don't mean much in a patch cable.  But your scheme splits the
pairs, which is asking for noise interference, especially crosstalk.
Also, be sure no more than 1" of the cable end is "untwisted" to crimp
the plug.

> To recap, although the wiring and PC Nics can do 100 MPS, the hubs and > the connection to the HP 3000 are keeping the actual speed to 10 MPS.
> So, this switch is the first time that parts of the network are being
> (or could be, at least) allowed to run at 100 MPS. If it would work. I
>  am going to try this other wiring scheme on my PC, but just wondered
> if anyone else could shed some light. TIA

Your 3000 will only do 10Mb to the MFIO card adapter.  If you have a
100BT card, hard code it to 100Mb/FDX in NMMGR and configure your switch
accordingly.  It isn't clear what all is connected to your "hub" but
depending on it's intelligence (is it 100Mb capable at all?  Does it
really support 10/100 mixed?) it might limit all connections to 10Mb.

You can check http://www.lanshack.com/highlights/cat5notes.htm, among
other places, for further details.

Jeff

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