Description 1
This indicates the depth of the queue/scheduler hierarchy. A value of 0 indicates that there is no hierarchy and that all queues/schedulers are port-bound. 0 - No hierarchy 1 - S1 schedulers (attached to the egress port) 2 - S2 schedulers (next level attached to the S1 schecdulers) 3 - S3 schedulers (attached to the COS queues)
Sources for this description
Multiple manufacturers; see the original MIB MIB copies (LibreNMS/Observium Community)