The throughput for the bandrich dongle was limited to 13Mb/s in downlink
UDP with iperf, with lots of packets lost (we sent 15Mb/s). TCP was
working fine.

Replacing /dev/ttyUSB2 by /dev/ttyUSB0 for wvdial solves the issue.

We also had to have separate data/control links. (See bandrich.txt
in cmake_targets/autotests/v2/actions for full details.)