You use the IPQoS flowacct module to track traffic flows for billing or network management purposes. Your QoS policy should include flow accounting in the following circumstances:
Your company offers SLAs to customers.
Review the SLAs to determine what types of network traffic your company wants to bill customers for. Then, review your QoS policy to determine which classes select traffic to be billed.
You have applications that might need monitoring or testing to avoid network problems.
Consider using flow accounting to observe the behavior of these applications. Review your QoS policy to determine the classes that you have assigned to traffic that requires monitoring.
Mark Y in the flow-accounting column for each class that requires flow accounting in your QoS planning table.