This read-write CmPmIntervalType value sets the fine-grained performance-monitoring collection interval for every monitored PM entity on the Ethernet NTE GE206F card, choosing between interval-5min and interval-15min, with interval-15min as the default. It matters to an administrator tuning visibility into short-lived error bursts, since a 5-minute bucket surfaces problems that a 15-minute bucket would average away. For example, an engineer chasing an intermittent errored-seconds spike on the Ethernet NTE GE206F card would set this OID to interval-5min to get finer time resolution on the PM counters, instead of relying on interval-1day rollups.