Because channels physically belong to trunks and logically belong to channel groups, the characteristics of each channel are defined with several different groups of parameters:
The way the parameter groups are used to define channel and trunk characteristics is shown in Figure 1. If you use System Configuration to define the telephony environment, you need to understand these relationships; if you use Pack Configuration, all you need to know is that the same parameters are being set, but Pack Configuration is keeping track of the relationships for you.