6.1.8. Types of Charge Calculation 
The charge calculation has been adjusted to meet the new Euro-ISDN
requirements and the requirement for a calculation done without call
charge units. The following types of charge calculation are used:
- Charge calculation for internal traffic over internal zones (maximum of 9); the zones can be allocated by ITR group. The cost parameter of the ITR group in which the chargeable station is located always applies.
- Charge calculation with call charge units (price/call charge unit)
- Charge calculation with amounts (factor)
- Charge calculation for Euro-ISDN with cost parameters that are reported by the trunk (AOC-S, AOC-D, and AOC-E).
- Charge calculation without charge information based on cost parameters (CARRIER and ZONE) and length of the connection.
You can assign different prices for variable clocks (for example, for
n sec. connection duration) for each cost parameter and time of day (which
can also vary for each cost parameter). Different rate period tables
and minimum and basic charges can be taken into account for each cost
parameter.
If the network signals charge information, this information is included
when calculating the charges.
The charge calculation is done centrally in the call detail recording.
The calculated charges are passed on to the call processing and shown
on the telephone station's Digite display (CDRD).