limit iBook's modem speed?

I'm trying to dial up to the Internet via a local number in Brazil
using an Apple iBook 700 with Mac OS X 10.2.4 and its internal modem.
For three out of four local ISPs the PPP session drops seconds after it
has completely been established. With the fourth ISP I get a 33600
connection. I suspect that my local phone line is of bad quality only,
maybe using some PCM technique.
One way to mitigate those problems would be to explicitely limit the
modem's
connection speed to, say, V.34 at 192000.
How can this be accomplished with the internal modem? I assue there are no
AT commands? Any help would be appreciated.
Thanks.

geos.DeleteThis@epost.de (Georg Schwarz) wrote:

> One way to mitigate those problems would be to explicitely limit the
> modem's
> connection speed to, say, V.34 at 192000.
> How can this be accomplished with the internal modem? I assue there are no
> AT commands? Any help would be appreciated.

Under MacOS 9, the Modem control panel lets you choose from a list of
modem types. One of them is "Apple Internal 56K Modem (v.90)", which is
the usual one. But there's also "Apple Internal 56K Modem (v.34)", which
would probably do what you want. It worked that way for me when I had
connection problems while traveling.

I haven't yet made the step to OS X (we're a multiple-Mac family with lots
of inertia), so I can't point to the corresponding configuration change
there, but maybe this will be enough of a hint for you to find what you're
looking for.