[svlug] help transfering data over 1394 cable

[Karen Shaeffer]

On Thu, May 08, 2008 at 10:19:56AM -0700, Daniel Gimpelevich wrote:
> On Thu, 08 May 2008 01:45:09 -0700, Rick Moen wrote:
> 
> > If in your experience you weren't able to get full duplex, and you _did_
> > try "locking" the ports to that mode, then I rather suspect the problem's
> > with one of the ports, rather than any inherent inability to do full
> > duplex over crossover cables.
> 
> I've tried locking pairs of 10Mb ports to full on both sides without
> success when the same worked through a 10/100 switch, and I've done the
> same with pairs of 100Mb ports, but admittedly, I've never tried it with
> pairs of 1000Mb ports, because by that time, I had no expectation of it
> working. Maybe I should indeed try that at some point.

I'm not mentioning any chipsets here, but there are a number of
1000/100/10 Mb NICs in the market today that are apparently tuned for
the 1000 Mb channel, and they can behave badly when attempting to use
them at 100/10. And that has nothing to do with the switch, although
there are other cases where the scope of the failure includes the
switch and switch settings as well. I know of one example where the
1000/100/10 Mb NIC will always link mismatch when used at 100 Mb
auto. And then, that NIC can actually lock up with the channel (PHY)
failing -- once the link mismatch happens, requiring cold reboot to
clear the failure.

You just have to know what chipsets you are using, cause some of
them aren't very well designed.

Thanks,
Karen
-- 
 Karen Shaeffer
 Neuralscape, Palo Alto, Ca. 94306
 shaeffer at neuralscape.com  http://www.neuralscape.com