linux, vgetty and a Netcomm Roadster V.92 USB (AM5055) modem

Ever tried to get the Netcomm Roadster V.92 USB (AM5055) modem working with vgetty? It isn't obvious and there is almost no documentation out there on how to make it happen. Following a few hours experimenting...

In /etc/mgetty+sendfax/voice.conf you need:

port_speed 115200
rec_silence_threshold 128
forceV253subset true
ring_report_delay 10

Then you need to record your actuall message, save it as a .wav file and then convert it to the appropriate format for the modem:

wavtopvf message.wav | pvfspeed -s 8000 | pvftormd V253modem 8 > /var/spool/voice/messages/standard.rmd

And that's about it.