There is no separate trunk group database. A trunk group exists as a result of being specified in the Trunk Group Name field of the Fax Line Database.
Trunk groups are intended mainly for high volume users that utilize different types of fax phone lines (for example, WATS lines or foreign exchange lines).
If you have multiple lines but they are all the same type, then you do not need to use Trunk Groups. In this case, give the same Trunk Group name to all of your lines.
See Using the Tariff Database for an explanation of how to use this feature.