1. A collector within a plurality of collectors in a network subscriber usage recording system, said collector comprising: an encapsulator for reading a plurality of network subscriber metadata records from a network data source and converting the network subscriber metadata records to a plurality of data normalized metered events; an aggregator for processing the data normalized metered events to create aggregated normalized metered events; a storage system; and an auditor for collecting audit metadata from said collector and generating audit normalized metered events based on the data normalized metered events, wherein the auditor transfers the audit normalized metered events from a volatile memory to a persistent storage in the storage system periodically at a constant time interval.