Perhaps the most useful application of SCU is when a source class is combined with an accounting profile. Instead of using show commands to observe SCU data, you can use an accounting profile to capture this information in a log file. This allows you to monitor and view SCU traffic statistics at your convenience.
A class usage profile collects destination or source traffic class statistics for interfaces that have the appropriate traffic class feature enabled. The profile logs these statistics by means of a file specified at the [edit accounting-options] hierarchy level. This accounting profile is a superset of the previously released destination class profile. In JUNOS Release 5.4 and later, source class profiles and destination class profiles are part of class usage profiles.
A class usage profile can collect statistics for either source or destination class usage. The destination-classes and source-classes fields are mutually exclusive and indicate the type of statistics that are collected.
To enable SCU accounting profiles, perform these steps:
To view a sample accounting profile log, see Verifying Your Work .