Egress Port Scheduler Overrides - Alcatel-Lucent 7950 Quality Of Service Manual

Configuring Port Scheduler Policies

Egress Port Scheduler Overrides

Once a port scheduler has been associated with an egress port, it is possible to override the
following parameters:
•
•
•
The orphan priority level (level 1) has no configuration parameters and cannot be overridden.
Weighted Scheduler Group in a Port Scheduler Policy
The existing port scheduler policy defines a set of eight priority levels with no ability of grouping
levels within a single priority. In order to allow for the application of a scheduling weight to
groups of queues competing at the same priority level of the port scheduler policy applied to the
Ethernet port, a new group object is defined under the port scheduler policy:
CLI Syntax: configure>qos>port-scheduler-policy>group group-name rate
pir-rate[cir cir-rate]
Up to eight groups can be defined within each port scheduler policy. One or more levels can map
to the same group. A group has a rate and optionally a cir-rate and inherits the highest scheduling
priority of its member levels.
In essence, a group receives bandwidth from the port and distributes it within the member levels
of the group according to the weight of each level within the group. Each priority level will
compete for bandwidth within the group based on its weight under congestion situation. If there is
no congestion, a priority level can achieve up to its rate (cir-rate) worth of bandwidth.
The mapping of a level to a group is performed as follows:
CLI Syntax: configure>qos>port-scheduler-policy>level priority-level rate
pir-rate [cir cir-rate]
Note that CLI will enforce that mapping of levels to a group are contiguous. In other words, a user
would not be able to add priority level to group unless the resulting set of priority levels is
contiguous.
When a level is not explicitly mapped to any group, it maps directly to the root of the port
scheduler at its own priority like in existing behavior.
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The max-rate allowed for the scheduler.
The maximum rate for each priority level 8 through 1.
The CIR associated with each priority level 8 through 1.
group group-name [weight weight-in-group]
7950 XRS Quality of Service Guide