Description: Charging Gateway table. Charging information in GPRS is collected for each MS by SGSNs and GGSNs that are serving the MS. The information that the operator uses to generate the bill to a subscriber is operator-specific, such as usage of the radio interface, PDP addresses, duration of PDP context, usage of general GPRS resources, location of MS, traffic distination, usage of external data network and so on. Charging Gateways act as a storage buffer for real time Charging Data Record (CDR) collection. It provides the CDRs to the billing system. Charging Gateway Table lists all the charging gateways and their operational states. Backup charging gateway type is not allowed if there is no primary charging gateway type entry in the table. In addition, there is only one primary charging gateway entry.