AL2 route endpoint endpoint endpoint endpoint group group group group VCCep VCCep VCCep VOCep V OCep VCCep VCCep VCCep AAL type 2 connection AAL type 2 connection virtual channel (VC) virtual channel (VC) Figure 4.36 Digit analysis and routing components in the MGW (AAL2) Configuring Charging in the MSS Charging of the calls in the MSS is similar to charging in the MSC. In principle, the same call detail record (CDR) is created from events related or not related to calls, such as mobile originated calls (MOCs) supplementary service execution (SUPS). A detailed description of the changes in the CDR content is available from a CDR field description. However, the account principles of interswitch traffic of the calls using the IP or ATM transport are divided into two different levels: user plane accounting; control plane accounting. The accounting of traffic using TDM circuits is not changed. It is recommended that multiple UPDRs should be defined in such a way as to differentiate between control plane accounting of the different MSSs within the release 4 network. At least one UPDR should be configured towards each MSS. Similarly, if more detailed accounting of different user plane resources between own MSC servers is needed, multiple UPDs should be defined towards the MGWs controlled by other MSSs. Defining the basis of charging involves the following steps: Origin analysis. The origin analysis examines the cell tariff, the cell category and the classmark of the mobile station. The result of the analysis is the charging origin (CORG). Core Network Planning and Optimisation Digit analysis. The digit analysis examines the origin data and the dialled digits. As a result of the analysis, the system receives information on routing and charging control. Charging analysis. The charging analysis receives the digit analysis result data and the call origin, and uses these to define a charging case containing the charging characteristics for the call. The related source data templates for configuring charging in the MSS are c