21143:Asymmetric result

devdrvr devdrvr@davis.com
Sat Jul 10 21:46:42 1999


With the 21143-TD or PD what is the right way to specify to one versus the
other?  I have a MII transceiver on a CardBus card (I think) and I want to make
it work.  What is the official way to know for your PHY which one you are
dealing with; glean it from the manual is my guess?

Do you know a place that discusses the history of the transceiver types?

--Lu Gregg
Device Driver Programmer
Davis, CA

Donald Becker wrote:

> On Sat, 10 Jul 1999 hyun2@dirac.uos.ac.kr wrote:
> > Recently I bought a card from dintek(taiwan) based on 21142PD. I installed
> > it on a x86 machine and connect to another machine with 3com905-TX using
> > a twisted cable.
> >
> > Using a tulip drive 0.91e  I could make my machine to get network. Then
> > I tested transfer rate using ttcp. I get an asymmetric result. From tulip
> > to 3com:10217.37 KB/sec, while from 3com to tulip: 185.41 KB/sec. Yes
> > there is factor five or six difference.
> ...
> > I have enabled the tulip module with the option
> > options=5  debug=3.
> That's your problem.
> You have specified the SYM transceiver type, when you have a MII
> transceiver.
> The link will work properly if you use the default setting and allow the
> duplex to be negotiated.
> Donald Becker                                     becker@cesdis.gsfc.nasa.gov
> USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
> Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771
> 301-286-0882         http://cesdis.gsfc.nasa.gov/people/becker/whoiam.html