Flow Record Table

The flowacct module maintains a flow table that records all packet flows that are seen by a flowacct instance. A flow is identified by the following parameters, which comprise the flowacct 8–tuple.

• Source address

• Destination address

• Source port

• Destination port

• DSCP

• User ID

• Project ID

• Protocol

If all the parameters of the 8–tuple for a flow remain the same, the flow table contains only one entry. The max_limit parameter determines the number of entries that a flow table can contain.

The flow table is scanned at the interval that is specified in the IPQoS configuration file for the timer parameter. The default is 15 seconds. A flow “times out” when its packets are not seen by the IPQoS system for at least the timeout interval in the IPQoS configuration file. The default time-out interval is 60 seconds. Entries that have timed out are then written to the accounting file that is created with the acctadm command.