IPQoS adds the flowacct accounting module to the Diffserv model. You can use flowacct to gather statistics on traffic flows, and bill customers in agreement with their SLAs. Flow accounting is also useful for capacity planning and system monitoring.
The flowacct module works with the acctadm command to create an accounting log file. A basic log includes the IPQoS 5-tuple and two additional attributes:
Source address
Source port
Destination address
Destination port
Protocol number
Number of packets
Number of bytes
You can also gather statistics on other attributes, as described in Recording Information About Traffic Flows, and in the flowacct (7ipp) and acctadm (1M) man pages.
For information about planning a flow-accounting strategy, see Planning for Flow Accounting.