Name this setup as gct21 or something similar. The iMac does not use this information; it is only to differentiate between accounts. In other words, you may have an account for home use, and another account for work, each with different settings. Most iMacs for home use will be connected to ConnectTo.Net via a modem (which is built-in). Select modem. Click the right arrow at the lower-right of this screen.

If you are using the iMac's internal 56k modem, select iMac Internal 56k. If you have another modem, either internal or external, select that option. If you are using the internal modem, select internal modem. If not, check your modem manual. If you have tone dialing, select tone. Leave the "Ignore dial tone" box unchecked. Otherwise, your iMac will attempt to access ConnectTo.Net even if it shouldn't (i.e., someone else is on the phone.) Click the right arrow at the lower-right of this screen.