The committed burst size (CBS) parameters specify the amount of buffers that can be drawn from the reserved buffer portion of the queue’s buffer pool. After the reserved buffers for a specific queue have been used, the queue contends with other queues for additional buffer resources up to the maximum burst size.
The CBS of the queue is configurable under the different QoS policies, if supported by the platform, that provide the options to configure the queue parameters; for example, under service ingress and service egress queue policies, access port policies, network queue policies, and so on. The CBS for a queue is specified in kbytes.
For 7210 SAS-D and 7210 SAS-Dxp, the CBS for the queues is not configurable. The CBS value for the queues is set to appropriate default values that take care of specific FC needs in terms of maintaining the differential treatment. The default values used on different ports are listed in Table: Default CBS and MBS values.