a computer - implement method and system are provided for processing traffic flow statistics relating to data transmissions between computers connected to a computer network . traffic flow statistics gathered from network devices are processed in a series of enhancing steps to produce records for each unique combination of source ip address and destination ip address . the records contain corresponding details for each transmission including amount of data transmitted , transmission start and end times , and identification of the isps serving the source and destination computers . the records may be further enhanced to include categorization of each transmission according to the business relationship between the isps serving the source and destination computers . the records may be used as desired , such as for network accounting purposes or for generating bills to customers of an isp , according to billing rates the isp may assign in relation to the various parameters contained in the records .