USRobotics V.34 - Manual (Page 176)

COURIER HIGH SPEED MODEMS
Synchronous Operations F-11
Modulation/Connection Rate (Bn, &Nn)
Use the following guidelines for your Courier type. V.Fast
Class does not support synchronous mode.
V.32 terbo modems
If the modem is connecting with another U.S. Robotics V.32
terbo modem, set both modems to B0 and to a variable
connection rate, &N0. The modems will connect at the highest
possible rate.
If the Courier V.32 terbo is to connect with a V.32 modem, set
the Courier to B0 and try a variable connection rate first, &N0.
If that doesn't work, try a fixed connection rate of &N6 (9600
bps) or &N3 (2400 bps).
Modems in HST mode
HST modulation for synchronous communications is not
supported.
Dual Standard modems
Set the Dual Standard modem to B0. Try a variable connection
rate setting (&N0) first. If that doesn't work, you may have to
set a fixed connection rate, for example, &N6 (9600 bps).
NOTE: If your modem is set to a fixed rate, and the remote
modem is not set to the same rate, your modem hangs up.
Connection Rate (&Nn)
Use this command to set variable or fixed rates at the link
interface. The default is &N0, variable rate. The Courier
negotiates with the remote modem for the highest possible
connection rate, depending on the capabilities of the remote
modem. If &N0 does not work, try a fixed rate.
NOTE: The modem is not capable of connecting at 21.6K bps in
synchronous mode.
When you set the modem to a fixed rate, it will only connect if
the remote modem is operating at the same rate. If not, your
modem hangs up.