Multitech MultiModem MT5634ZPW-PCI Owner's Manual page 36

Owner's Manual
9. If you must dial 9 to get an outside line, edit the dialing prefix
to include a 9 and a comma, e.g., ATDT9, (the comma
inserts a pause before dialing the next digit). Similarly, to
turn off call waiting for the duration of the call, insert the
disabling code used in your area, e.g., ATDT*70,. If you are
using Windows 95-compliant software, make these changes
in the "How I dial from this location" box of the Dialing
Properties sheet.
*:
*70 is only used in the United States.
36 MT5634ZPW-PCI