At first sight, it would appear from the Modem Manager's MakeCall method that the baud rate and other communications parameters can be set in the parameters to this method. However, what is being set is actually the parameters pertaining to local communication with the modem, not parameters for communication between the local and remote modem.
The only way that particular parameters for the modem – modem link can be set is by setting a specific initialization string for the modem.
If you want to use specific parameters for different destination locations, then it is necessary to define cloned "ghost" modems in the system configuration. This is discussed in the section that follows.