Alcatel-Lucent 7450 Quality Of Service Manual page 172

Network Queue QoS Policy Command Reference
This command only applies to the 7450 ESS and 7750 SR.
Parameters adaptation-rule — Specifies the adaptation rule to be used while computing the operational PIR
mbs
Syntax mbs {size [byte | kilobytes] | default}
no mbs
Context config>qos>network-queue>egress-hsmda>queue
Description
The Maximum Burst Size (mbs) command specifies the relative amount of the buffer pool space for
the maximum buffers for a specific HSMDA queue.
The MBS value is used to by a queue to determine whether it has exhausted its total allowed buffers
while enqueuing packets. Once the queue has exceeded its maximum amount of buffers, all packets
are discarded until the queue transmits a packet. A queue that has not exceeded its MBS size is not
guaranteed that a buffer will be available when needed or that the packet's RED slope will not force
the discard of the packet. Setting proper CBS parameters and controlling CBS oversubscription is one
major safeguard to queue starvation (when a queue does not receive its fair share of buffers). Another
is properly setting the RED slope parameters for the needs of the network queues.
The no form of the command returns the MBS size for the queue to the default for the forwarding class.
This command only applies to the 7450 ESS and 7750 SR.
Parameters size — Specifies the size of the MBS for the HSMDA queue.
bytes — Identifies the size value in terms of bytes.
kilobytes — Identifies the size value in terms of kilobytes.
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value.
Values pir — Defines the constraints enforced when adapting the PIR
rate defined. The pir parameter requires a qualifier that defines
the constraint used when deriving the operational PIR for the
HSMDA queue. When the pir command is not specified, the
default applies.
max — The max (maximum) option is mutually exclusive with
the min and closest options.
min — The min (minimum) option is mutually exclusive with the
max and closest options.
Default closest — The closest parameter is mutually exclusive with the
min and max parameter. When closest is defined, the operational
PIR for the HSMDA queue will be the rate closest to the rate
specified using the rate command
Values
0 to 2688000 (for bytes)
0 to 2625 (for kilobytes)
Quality of Service Guide