Alcatel-Lucent 7750 Configuration Manual page 563

size of the increment will not cause the bucket's depth to equal or exceed a higher priority threshold. It also
ensures that an unfair packet within a priority level cannot cause the PIR bucket to increment to the discard-
all threshold within the priority.
When evaluating maximum packet size, each child policer's per-packet-offset setting should be taken into
consideration. If the maximum size packet is 1518 bytes and a per-packet-offset parameter is configured to
add 20 bytes per packet, min-thresh-separation should be set to 1538 due to the fact that the parent policer
will increment its PIR bucket using the extra 20 bytes.
In most circumstances, a value larger than the maximum packet size is not necessary. Management of prior-
ity level aggregate burst tolerance is intended to be implemented using the priority level mbs-contribution
command. Setting a value larger than the maximum packet size will not adversely affect the policer perfor-
mance, but it may increase the aggregate burst tolerance for each priority level.
One thing to note is that a priority level's shared-portion of the parent policer's PIR bucket depth is only nec-
essary to provide some separation between a lower priority's discard-all threshold and this priority's discard-
unfair threshold. It is expected that the burst tolerance for the unfair packets is relatively minimal since the
child policers feeding the parent policer priority level all have some amount of fair burst before entering into
an FIR exceed or unfair state. The fair burst amount for a priority level is defined using the mbs-contribution
command.
The no form of this command returns the policy's min-thresh-separation value to the default value. This
has no effect on instances of the parent policer where min-thresh-separation is overridden unless the over-
ride is removed.
Default
no min-thresh-separation
Parameters size [bytes | kilobytes] — The size parameter is required when executing the min-thresh-separation
command. It is expressed as an integer and specifies the shared portion in bytes or kilobytes that is
selected by the trailing bytes or kilobytes keywords. If both bytes and kilobytes are missing, kilobytes is
the assumed value. Setting this value has no effect on parent policer instances where the min-thresh-
separation value has been overridden. Clearing an override on parent policer instance causes this value
to be enforced.
Values
Default
[bytes | kilobytes] — The bytes keyword is optional and is mutually exclusive with the kilobytes keyword.
When specified, size is interpreted as specifying the size of min-thresh-separation in bytes.
The kilobytes keyword is optional and is mutually exclusive with the bytes keyword. When specified,
size is interpreted as specifying the size of min-thresh-separation in kilobytes.
Values
Default
priority
Syntax priority level
Context config>card>fp>ingress>access>queue-group>policer-control-override>priority-mbs-thresholds
config>card>fp>ingress>network>queue-group>policer-control-override>priority-mbs-thresholds
7750 SR Interface Configuration Guide
0 – 16777216
none
bytes or kilobytes
kilobytes
Interface Configuration
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