The maximum burst size (MBS) parameter specifies the maximum queue depth to which a queue can grow. This parameter ensures that a customer that is massively or continuously oversubscribing the PIR of a queue will not consume all the available buffer resources. For high-priority FC service queues, the MBS can be relatively smaller than the other FC queues because the high-priority service packets are scheduled with priority over other service FCs.
The MBS 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 MBS for a queue is specified in Kbytes.
On 7210 SAS-D and 7210 SAS-Dxp, the MBS for the queues is not configurable. The MBS 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.