Trailblazer gets mad at AT&T 3b1 OBM (on board modem)

[Bill Mayhew]

Hi,

I recently had the occasion to call an AT&T 3b1's on board modem
from my Trailblazer.  When the trailblazer placed the data call at
1200 baud into the 3b1 OBM, it thought that the 3b1 had MNP
protocol, as reported by the Telebit's "CONNECT 1200/REL".  At that
point, the Trailblazer locked up, and I had to drop the DTR lead to
get it to disconnect.

The moral of the story is that you need to set "ATS95=0" before
dialing into a 3b1 to disable the Trailblazer from trying MNP on
the connection.   The default setting should be "ATS95=2" so that
the Trailblazer will use MNP if the other end has MNP and not use
MNP if the other end is a vanilla modem.  The only place this ever
seems to have gotten me into troulbe is with the 3b1's OBM.

So the question is, is the 3b1's OBM really supposed to be an MNP
modem, and this 3b1 is sick?  Or is the 3b1 an incomplete
implementation of MNP, that never really was supposed to work?  The
3b1's manuals don't say anything one way or the other about MNP.

Bugs!...

--Bill