On Fri, 12 Sep 1997, Brain fried.  Explanation is in file core. wrote:

> Anyone want to fill me in?  I don't want to do a fallback; I'm going
> slow enough as it is...
> 
> #### begin modem ati6 output ####
>
> [ .. beautifully formatted statistics .. ]
>
> Disconnect Reason is Unable to Retrain
> #### end modem ati6 output ####

You modem is disconnecting because of your phone-line quality, not because
of a lost carrier or forced hang-up on your end.  This vindicates PPP from
all guilt! =)

I have a Supra 28.8 and boy is it picky.  I get so many retrains with it
at 28,800 V.34 that I actually get better throughput by reducing the
connect rate to 21600.  I suspect that my main problem is an
incompatibility with my ISPs remote modem.  It's possible that this may be
your problem as well.

-J