I've been experimenting with getting a PPP connection running, but I've
run up against a wall.  I have a GV Teleport Gold, which has been working
fine.  Sometime yesterday, for no obvious reason, NetBSD decided it didn't
want to talk to the serial ports anymore.  The utility "tip" tries for
about 6-7 seconds, then reports "link dead".  The utility "cu" says it has
a connection (to the device, that is, not to a remote site) but as soon as
it tries to send a character it fails with an I/O error.

I've tried the modem on both the modem and printer ports, and I've tried
using the installer to rebuild the device files.  (The modem works fine on
the mac side, BTW.)  It used to work just fine.... any ideas?  Any
diagnostic tools that might be useful?  I'm out of ideas.

Thanks,
Brian