RADIUS

Accounting

Rounding out the AAA framework is accounting, which measures and documents the resources a user takes advantage of during access. This can include the amount of system time or the amount of data a user has sent and/or received during a session. Accounting is carried out by the logging of session statistics and usage information and is used for authorization control, billing, trend analysis, resource utilization, and capacity-planning activities.

Accounting data has several uses. An administrator can analyze successful requests to determine capacity and predict future system load. A business owner can track time spent on certain services and bill accordingly. A security analyzer can look at denied requests, see if a pattern emerges, and possibly ward off a hacker or freeloader. The moral here is that the accounting data is of great utility to an AAA server administrator. I’ll cover many uses of accounting data and strategies for getting the most out of the logs in Chapter 4 and Chapter 7.