The GeoPort internal modem does not have a Telephone Setup control panel. All of the functionality of the Telephone Setup control panel is incorporated in the Express Modem control panel. Many of the settings which one must enter manually are automatically calculated by the sophisticated algorithms that are part of the GeoPort software.
You should disregard references to the Telephone Setup control panel within the Megaphone documentation.
Even if you are able to find and use a Telephone Setup control panel, you will see absolutely no benefit; it will be ignored by the Megaphone software.