Comtrol RocketPort USB Serial or Modem Hub Driver Installation with Windows 98 - Manual (Page 18)

Installing Modems on the Serial Ports 18
8. To add more modems, click the Add button and repeat Steps 3 through 7.
9. Optionally:
a. Click the Dialing Properties button to configure basic phone service information.
b. Select a modem and click the Properties button to configure port speed, data bits, parity, and so on.
c. Click the Diagnostics tab, then select a port and click More Info to query and test the modem.
10. When you are done, click OK to exit the Modem Properties screen. Your changes take effect immediately.
No reboot is required.