With each button, one certain Connection type is used, in the Advanced Mode. The Connections are operator specific and dependent on which operator you have chosen during installation.
Below, as an example, you can view the Connection for T-Mobile
Germany that is linked to the buttons in the TMCC UI and that can
be edited to be functional in any other T-Mobile GPRS
TMD GPRS Internet This connection is linked to the “Email”, “Internet” and “Connect” buttons.
The Connections list box is intended as a toolbox which you can use to define several different connections for GPRS. You can choose the GPRS connection type by selecting the relevant radio button.