wfFrSwUsageStoreInterval 1.3.6.1.4.1.18.3.5.9.6.5.8

This number specifies the interval (number of minutes) for the Billing process to write billing usage data on to the file system from the wfFrSwUsage MIB. Note: When converted to seconds, this must be a multiple of wfFrSwUsageTimerInterval.