If you don't object, you can extends your knowledge of this hour's topics with the following activities:

  • Create an AcousticModem class with a speed of 300 and its own connect() method.
  • Add a disconnect() method to one of the classes in the Modem project, deciding where it should go to support modem disconnection in cable, DSL, and acoustic modems.

To see Java programs that implement these activities, visit the tutorial's website at