It will allow you to save a copy of your current MacTCP settings in a file. You can then switch between the two sets of settings by double-clicking on the appropriate settings file for your current connection method. Later, once you have the connection working, you can increase this speed. See the table below for more information. For Tone vs. Pulse dialing, choose whichever you have in your phone system.
Most people have Tone dialing.
For Phone Number, fill in the phone number you plan to use to dial in. Otherwise, if a call comes in while you are on-line, you will be disconnected. For Modem Init, don't fill in anything at first. Everything else should remain at the default settings. Type ppp at the prompt.