Subject: Re: How does 10baseT/FDX work?
To: None <firstname.lastname@example.org>
From: Jason Thorpe <email@example.com>
Date: 09/25/1999 19:19:10
On Sat, 25 Sep 1999 13:25:36 -0700
"Justin C. Walker" <firstname.lastname@example.org> wrote:
> - external loopback is normally a diagnostic mode, so I don't know
> if the device would work differently than in "normal mode (does it
> require a loopback connector?); and
Agreed... in order for it to work, the chip has to be physically
wired to the board in such a way as it won't provide the loopback
> - this definitely won't get you N-way (autonegotiation) support,
> but most (some?) switches are configurable for this feature (finding
> out about it is another trick). However, hubs and switches won't
> default to FDX, so for general use, you're looking at some trouble.
> If you're using this in a limited, controlled environment, it may
Right, but this is the same problem you have if you have one of
the original DEC Tulip chips (a 21040). They could do full-duplex,
but Nway didn't appear in that line until the 21041 (which had a very
limited Nway block specifically for negotiating FDX with switches).
-- Jason R. Thorpe <email@example.com>