If the connector is loose, or disconnected from the port, do not push the connector in when the computer is powered. This could cause a power surge which could damage the system. Power down the computer, then re-seat the connection to the computer and restart. The cable that runs between the computer and modem could be faulty or the cable could be an incorrect type. The cable that runs from the modem to the computer is often supplied with the modem.
Hardware handshaking means that the hardware controls the data flow.
If there is a control panel that corresponds to the modem name, make sure the modem is switched on and reads ready for modem connection. Modems often come with a suite of fax and Internet applications. Familiarize yourself with any software packages that come with the modem by reviewing documentation. Open Transport PPP is pre-installed on many of the newest models of Macintoshes as a part of System 8.0. Check with the telephone company, or look in the telephone book, for the proper touch tone sequence to disable these services.