Alcatel-Lucent 7450 Quality Of Service Manual page 798

HSMDA Command Reference
class-tier
Syntax class-tier
Context config>qos>hsmda-pool-policy
Description This class enables the context to configure class pool tier parameters. Within the class-tier context,
class pools may be associated with a root pool and are sized as a percentage of the root pool's size.
class-pool
Syntax class-pool class-pool-id root-parent root-pool-id allocation-percent percent-of-parent-pool
no class-pool class-pool-id
Context config>qos>hsmda-pool-policy
Description This command specifies a class pool's root pool parent and define the buffer allocation percentage
used for sizing the class pool relative to the parent pool's size. Eight class pools exist and do not need
to be created.
Class pools function as a scheduling class aggregate buffer control mechanism and define the total
number of buffers a given scheduling class may consume for all ports. Each class pool must be placed
in a root pool hierarchy. This is accomplished by the root-parent keyword and root-pool-id parameter.
A class pool cannot be parented by a root pool that currently has an allocation-weight parameter set to
0. Once a class pool is parented by a root pool, that root pool will not allow the allocation-weight to be
set to 0.
The allocation-percent keyword and associated percent-of-parent-pool parameter indirectly specifies
the size of the class pool. The percent value is multiplied by the size of the root pool to derive the class
pool size. If the percent value is changed, or the size of the root pool changes, the class pool and port
class pools associated with the class pool must be resized. The sum percent values for the class pools
associated with a root pool may exceed 100%, allowing the class pools to oversubscribe the root pool.
In this case, it is possible for the class pool to indicate that buffers remain when the root pool has
exhausted its available buffers.
When queues associated with the class pool's scheduling class request buffers due to packet arrival,
the port class pool, class pool and root pool must all have sufficient buffers available to place the packet
into the queue. If sufficient buffers are not available, the packet will be discarded by the queue.
The no form of the command restores the default root-parent and allocation-percent value for a class
pool. Based on the class pool, the restored default values may differ.
Parameters
class-pool-id — Specifies which class pool is being modified. This parameter is a required when
800
executing the class-pool command.
Values
1 — 8
Quality of Service Guide