You should have a
/dev/cuaU0 which is a USB dial out device. Have you entered a definition for this device in
/etc/remote?
Code:
# Sample dial out lines.
#
cua00|For hp300,i386,mac68k,macppc,mvmeppc,vax:\
:dv=/dev/cua00:tc=dialup:tc=unixhost:
cuaa|For sparc,mvme68k:\
:dv=/dev/cuaa:tc=dialup:tc=unixhost:
# USB version for i386
cuaU0|For hp300,i386,mac68k,macppc,mvmeppc,vax:\
:dv=/dev/cuaU0:tc=dialup:tc=unixhost: