User-Level Billing and Accounting in IP Networks

IP networks were originally designed by universities and government research agencies, and not by network operators with commercial objectives. As a result, while aggregate accounting is possible for network management, detailed accounting at the level of individual users is often not possible. In today's networks, this limitation now hinders the effective introduction of a variety of new IP-based services. Network operators lack the tools to minitor individual customers' use of network services, to measure the type and quality of service that they receive, and ultimately to establish service-level agreements and bill for those serivces. To meet these needs, this paper presents an approach to accounting in IP networks based on a special-purpose network probe, which we term a NetCounter. The key functionality of a NetCounter is real-time, in-network correlation of network traffic with the individual users that generated it. This approach has several technical advantages oveer alternative approaches. Most importantly, the NetCounter achieves substantial in-network aggregation, reducing the volume of usage data generated by between 2 and 4 orders of magnitude (when compared to flow-logging systems). In addition, NetCounters capture usage data at the level of individual users, and record detailed user- and service-specific performance metrics.