6.3.2.1. AOCC 
The AOCC parameter must always be set for CORNET-NQ tie trunks.
Otherwise no Advice of Charge (AOC) messages are sent over the tie trunk.
The COT parameter AOCC must also be set for QSIG and ETSI connections
to external systems, but only if the trunk also understands the Advice
of Charge request. Clarify this beforehand with the external manufacturer.
If the COT parameter AOCC is set but the trunk does not understand
the AOC request, the AOC class of service is suppressed. All AOC messages
that are received will be discarded.
More information you can find in section "INCDR - Feature Usage
Examples and COT Parameters, Chapter
262, "AOCC - Request charges per line for remote station".