Modems

With juse one modem, can i use it accept incoming calls for login and
also use it to dial out, so i can send out reports and collected data?
Right now, getty is setup correctly and can allow dial-ins to login, but
when the modem is used to dial out, the dial-out program competes with
getty for the port and results in mass confusion.

Can i get away with this without hacking getty?