Neither the COT parameter DFNN nor LWNC may be set for the circuit to the XPR because otherwise the paying party would be provided with the wrong account number (with the number of the tie trunk to the XPR).

A dialing analysis is made in the OpenScape 4000 with the calling party that the OpenScape 4000 receives from the XPR. Then the node number from the RICHT entry is established and, along with the calling party, is reported to the call detail recording function. In this way, the paying party (the calling party) is clearly identified.

More information you can find in section "INCDR - Feature Usage Examples and COT Parameters, Chapter 273, "LWNC - Line protocol without node number" and Chapter 267, "DFNN - Use default node number for trunk as a dummy source node number".