QoS Scheduler Policy Command Reference

This command copies existing QoS policy entries for a QoS policy to another QoS policy.

The copy command is a configuration level maintenance tool used to create new policies using existing policies. It also allows bulk modifications to an existing policy with the use of the overwrite keyword.

If overwrite is not specified, an error will occur if the destination policy exists.

Each scheduler policy is divided up into groups of schedulers based on the tier each scheduler is created under. A tier is used to give structure to the schedulers within a policy and define rules for parent scheduler associations.

The scheduler-policy command creates a scheduler policy or allows you to edit an existing policy.The policy defines the hierarchy and operating parameters for virtual schedulers. Merely creating a policy does not create the schedulers; it only provides a template for the schedulers to be created when the policy is associated with a SAP or multi-service site.

Each scheduler policy must have a unique name within the context of the system. Modifications made to an existing policy are executed on all schedulers that use the policy. This can cause queues or schedulers to become orphaned (invalid parent association) and adversely affect the ability of the system to enforce service level agreements (SLAs).

If a scheduler-policy-name does not exist, it is assumed that an attempt is being made to create a new policy. The success of the command execution is dependent on the following:

When the maximum number of scheduler policies has been exceeded a configuration error occurs, the command will not execute, and the CLI context will not change.

If the provided scheduler-policy-name is invalid according to the criteria below, a name syntax error occurs, the command will not execute, and the CLI context will not change.

The frame-based-accounting command is used to enable frame based for both the children queues parented to the scheduling policy and for the schedulers within the scheduler policy.

Once frame based accounting is enabled on the policy, all queues associated with the scheduler (through the parent command on each queue) will have their rate and CIR values interpreted as frame based values. When shaping, the queues will include the 12 byte Inter-Frame Gap (IFG) and 8 byte preamble for each packet scheduled out the queue. The profiling CIR threshold will also include the 20 byte frame encapsulation overhead. Statistics associated with the queue do not include the frame encapsulation overhead.

The scheduler policy’s scheduler rate and CIR values will be interpreted as frame based values.

The configuration of parent-location and frame-based-accounting in a scheduler policy is mutually exclusive to ensure consistency between the different scheduling levels.

The no frame-based-accounting command is used to return all schedulers within the policy and queues associated with the policy to the default packet based accounting mode. If frame-based-accounting is not currently enabled for the scheduling policy, the no frame-based-accounting command has no effect.

This command determines the expected location of the parent schedulers for the tier 1 schedulers configured with a parent command within the scheduler-policy. The parent schedulers must be configured within a scheduler-policy applied at the location corresponding to the parent-location parameter.

If a parent scheduler name does not exist at the specified location, the schedulers will not be parented and will be orphaned.

The configuration of parent-location and frame-based-accounting in a scheduler policy is mutually exclusive in order to ensure consistency between the different scheduling levels.

The no form of the command reverts to the default.

This command identifies the level of hierarchy that a group of schedulers are associated with. Within a tier level, a scheduler can be created or edited. Schedulers created within a tier can only be a child (take bandwidth from a scheduler in a higher tier). Tier levels increase sequentially with 1 being the highest tier. All tier 1 schedulers are considered to be root and cannot be a child of another scheduler. Schedulers defined in tiers other than 1 can also be root (parentless).

3 tiers (levels 1, 2 and 3) are supported.

The save config and show config commands only display information on scheduler tiers that contain defined schedulers. When all schedulers have been removed from a level, that level ceases to be included in output from these commands.

This command creates a new scheduler or edits an existing scheduler within the scheduler policy tier. A scheduler defines bandwidth controls that limit each child (other schedulers and queues) associated with the scheduler. Scheduler objects are created within the hierarchical tiers of the policy. It is assumed that each scheduler created will have queues or other schedulers defined as child associations. The scheduler can be a child (take bandwidth from a scheduler in a higher tier, except for schedulers created in tier 1). A total of 32 schedulers can be created within a single scheduler policy with no restriction on the distribution between the tiers.

Each scheduler must have a unique name within the context of the scheduler policy; however the same name can be reused in multiple scheduler policies. If scheduler-name already exists within the policy tier level (regardless of the inclusion of the keyword create), the context changes to that scheduler name for the purpose of editing the scheduler parameters. Modifications made to an existing scheduler are executed on all instantiated schedulers created through association with the policy of the edited scheduler. This can cause queues or schedulers to become orphaned (invalid parent association) and adversely affect the ability of the system to enforce service level agreements (SLAs).

If the scheduler-name exists within the policy on a different tier (regardless of the inclusion of the keyword create), an error occurs and the current CLI context will not change.

If the scheduler-name does not exist in this or another tier within the scheduler policy, it is assumed that an attempt is being made to create a scheduler of that name. The success of the command execution is dependent on the following:

When the maximum number of schedulers has been exceeded on the policy, a configuration error occurs and the command will not execute, nor will the CLI context change.

If the provided scheduler-name is invalid according to the criteria below, a name syntax error will occur, the command will not execute, and the CLI context will not change.

This command is used to enable (or disable) aggregate rate overrun protection on the agg-rate context.

This command defines an optional parent scheduler that is higher up the policy hierarchy. Only schedulers in tier levels 2 and 3 can have a parental association. When multiple schedulers and/or queues share a child status with the scheduler on the parent, the weight or strict parameters define how this scheduler contends with the other children for the parent’s bandwidth. The parent scheduler can be removed or changed at anytime and is immediately reflected on the schedulers created by association of this scheduler policy.

When a parent scheduler is defined without specifying weight or strict parameters, the default bandwidth access method is weight with a value of 1.

The no form of the command removes a child association with a parent scheduler. If a parent association does not currently exist, the command has no effect and returns without an error. Once a parent association has been removed, the former child scheduler attempts to operate based on its configured rate parameter. Removing the parent association on the scheduler within the policy will take effect immediately on all schedulers with scheduler-name that have been created using the scheduler-policy-name.

The port-parent command defines a child/parent association between an egress queue and a port based scheduler or between an intermediate service scheduler and a port based scheduler. The command may be issued in three distinct contexts; sap-egress queue queue-id, network-queue queue queue-id and scheduler-policy scheduler scheduler-name. The port-parent command allows for a set of within-CIR and above-CIR parameters that define the port priority levels and weights for the queue or scheduler. If the port-parent command is executed without any parameters, the default parameters are assumed.

In this context, the port-parent command is mutually exclusive to the parent command (used to create a parent/child association between a queue and an intermediate scheduler). Executing a port-parent command when a parent definition is in place causes the current intermediate scheduler association to be removed and replaced by the defined port-parent association. Executing a parent command when a port-parent definition exists causes the port scheduler association to be removed and replaced by the defined intermediate scheduler name.

Changing the parent context on a SAP egress policy queue may cause a SAP or subscriber context of the queue (policy associated with a SAP or subscriber profile) to enter an orphaned state. If an instance of a queue is created on a port or channel that does not have a port scheduler enabled and the sap-egress policy creating the queue has a port-parent association, the queue will be allowed to run according to its own rate parameters and will not be controlled by a virtual scheduling context. If an instance of a queue is on a port or channel that has a port scheduler configured and the sap-egress policy defines the queue as having a non-existent intermediate scheduler parent, the queue will be treated as an orphan and will be handled according to the current orphan behavior on the port scheduler.

The no form of this command removes a port scheduler parent association for the queue or scheduler. If a port scheduler is defined on the port which the queue or scheduler instance exists, the queue or scheduler will become orphaned if an port scheduler is configured on the egress port of the queue or scheduler.

The rate command defines the maximum bandwidth that the scheduler can offer its child queues or schedulers. The maximum rate is limited to the amount of bandwidth the scheduler can receive from its parent scheduler. If the scheduler has no parent, the maximum rate is assumed to be the amount available to the scheduler. When a parent is associated with the scheduler, the CIR parameter provides the amount of bandwidth to be considered during the parent scheduler’s ‘within CIR’ distribution phase.

The actual operating rate of the scheduler is limited by bandwidth constraints other then its maximum rate. The scheduler’s parent scheduler may not have the available bandwidth to meet the scheduler’s needs or the bandwidth available to the parent scheduler could be allocated to other child schedulers or child queues on the parent based on higher priority. The children of the scheduler may not need the maximum rate available to the scheduler due to insufficient offered load or limits to their own maximum rates.

When a scheduler is defined without specifying a rate, the default rate is max. If the scheduler is a root scheduler (no parent defined), the default maximum rate must be changed to an explicit value. Without this explicit value, the scheduler will assume that an infinite amount of bandwidth is available and allow all child queues and schedulers to operate at their maximum rates.

The no form of this command returns all queues created with this queue-id by association with the QoS policy to the default PIR and CIR parameters.

When a port scheduler has been associated with an egress port, it is possible to override the following parameters:

The orphan priority level (level 0) has no configuration parameters and cannot be overridden.

The no form of the command removes a port scheduler policy from the system. If the port scheduler policy is associated with an egress port or channel, the command will fail.

This command enables sharing of rates when the port on which this port-scheduler-policy is configured is part of a LAG configured in distribute mode.

When enabled, the absolute rate values configured as part of the max-rate, PIR/CIR group rates and PIR/CIR level rates are shared across the member ports of the LAG when configured in distribute mode.

This command does not have any affect when the port on which this port-scheduler-policy is configured is part of a LAG in link mode. Similarly when rates are configured as percent-active rates, the value of this object is irrelevant.

This command defines a weighted scheduler group within a port scheduler policy.

The port scheduler policy defines a set of eight priority levels. The weighted scheduler group allows for the application of a scheduling weight to groups of child queues competing at the same priority level of the port scheduler policy applied to a vport defined in the context of the egress of an Ethernet port or applied to the egress of an Ethernet port.

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 or from the vport 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 a congestion situation. If there is no congestion, a priority level can achieve up to its rate (cir-rate) worth of bandwidth.

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.

The no form of the command removes the group from the port scheduler policy.

The percent-rate command within the port scheduler policy group enables supports for a policer’s PIR and CIR rate to be configured as a percentage of the immediate parent root policer/arbiter rate or the FP capacity.

If the parent arbiter rate changes after the policer is created, the policer’s PIR and CIR rates will be recalculated based on the defined percentage value.

The rate and percent-rate commands override one another. If the current rate for a policer is defined using the percent-rate command and the rate command is executed, the percent-rate values are deleted. In a similar fashion, the percent-rate command causes any rate command values to be deleted. A policer’s rate may dynamically be changed back and forth from a percentage to an explicit rate at anytime.

The no form of this command returns the queue to its default shaping rate and cir rate.

This command specifies the total bandwidth and the within-cir bandwidth allocated to a weighted scheduler group.

This command configures an explicit within-cir bandwidth limit and a total bandwidth limit for each port scheduler’s priority level. To understand how to set the level rate and CIR parameters, a basic understanding of the port level scheduler bandwidth allocation mechanism is required. The port scheduler takes all available bandwidth for the port or channel (after the max-rate and any port egress-rate limits have been accounted for) and offers it to each of the eight priority levels twice.

The first pass is called the within-cir pass and consists of providing the available port bandwidth to each of the 8 priority levels starting with level 8 and moving down to level 1. Each level takes the offered load and distributes it to all child members that have a port-parent cir-level equal to the current priority level. (Any child with a cir-weight equal to 0 is skipped in this pass.) Each child may consume bandwidth up to the child’s frame based within-cir offered load. The remaining available port bandwidth is then offered to the next lower priority level until level 1 is reached.

The second pass is called the above-cir pass and consists of providing the remaining available port bandwidth to each of the eight priority levels a second time. Again, each level takes the offered load and distributes it to all child members that have a port-parent level equal to the current priority level. Each child may consume bandwidth up to the remainder of the child’s frame based offered load (some of the offered load may have been serviced during the within-cir pass). The remaining available port bandwidth is then offered to the next priority level until level 1 is again reached.

If the port scheduling policy is using the default orphan behavior (orphan-override has not been configured on the policy), the system then takes any remaining port bandwidth and allocates it to the orphan queues and scheduler on priority level 1. In a non-override orphan state, all orphans are attached to priority level 1 using a weight of 0. The 0 weight value causes the system to allocate bandwidth equally to all orphans based on each orphan queue or scheduler’s ability to use the bandwidth. If the policy has an orphan-override configured, the orphans are handled based on the override commands parameters in a similar fashion to properly parented queues and schedulers.

The port scheduler priority level command rate keyword is used to optionally limit the total amount of bandwidth that is allocated to a priority level (total for the within-cir and above-cir passes). The cir keyword optionally limits the first pass bandwidth allocated to the priority level during the within-cir pass.

When executing the level command, at least one of the optional keywords, rate or cir, must be specified. If neither keyword is included, the command will fail.

If a previous explicit value for rate or cir exists when the level command is executed, and either rate or cir is omitted, the previous value for the parameter is overwritten by the default value and the previous value is lost.

The configured priority level rate limits may be overridden at the egress port or channel using the egress-scheduler-override level priority-level command. When a scheduler instance has an override defined for a priority level, both the rate and cir values are overridden even when one of them is not explicitly expressed in the override command. For instance, if the cir kilobits-per-second portion of the override is not expressed, the scheduler instance defaults to not having a CIR rate limit for the priority level even when the port scheduler policy has an explicit CIR limit defined.

This command defines an explicit maximum frame based bandwidth limit for the port scheduler policies scheduler context. By default, once a scheduler policy is associated with a port or channel, the instance of the scheduler on the port automatically limit the bandwidth to the lesser of port or channel line rate and a possible egress-rate value (for Ethernet ports). If a max-rate is defined that is smaller than the port or channel rate, the expressed kilobits-per-second value is used instead. The max-rate command is another way to sub-rate the port or channel. This command can be used on channels only on the 7450 ESS and 7750 SR.

The max-rate command may be executed at anytime for an existing port-scheduler-policy. When a new max-rate is given for a policy, the system evaluates all instances of the policy to see if the configured rate is smaller than the available port or channel bandwidth. If the rate is smaller and the maximum rate is not currently overridden on the scheduler instance, the scheduler instance is updated with the new maximum rate value.

The max-rate value defined in the policy may be overridden on each scheduler instance. If the maximum rate is explicitly defined as an override on a port or channel, the policies max-rate value has no effect.

The no form of this command removes an explicit rate value from the port scheduler policy. Once removed, all instances of the scheduler policy on egress ports or channel are allowed to run at the available line rate unless the instance has a max-rate override in place.

This command defines the congestion monitoring threshold for the desired monitoring entity under the port-scheduler for per aggregate port-scheduler rate, per individual level, and per group that is aggregating multiple levels.

The congestion threshold is specified in percentages of the configured PIR rate for the entity for which congestion monitoring is desired. For example, if the configured PIR rate for level 1 is 100,000 Kbps, and the monitoring threshold is set to 90%, then an event where the offered rate is >90,000 Kbps will be recorded. This event is shown as part of the cumulative count of congestion threshold exceeds since the last clearing of the counters.

The no form of this command removes the congestion monitoring threshold.

This command override the default orphan behavior for port schedulers created using the port scheduler policy. The default orphan behavior is to give all orphan queues and schedulers bandwidth after all other properly parented queues and schedulers. Orphans by default do not receive any within-cir bandwidth and receive above-cir bandwidth after priority levels 8 through 1 have been allocated. The orphan-override command accepts the same parameters as the port-parent command in the SAP egress and network queue policy contexts. The defined parameters are used as a default port-parent association for any queue or scheduler on the port that the port scheduler policy is applied.

Orphan queues and schedulers are identified as:

A queue or scheduler may be properly parented to an upper level scheduler, but that scheduler may be orphaned. In this case, the queue or scheduler receives bandwidth from its parent scheduler based on the parent schedulers ability to receive bandwidth as an orphan.

Within-CIR Priority Level Parameters

The within-cir parameters define which port priority level the orphan queues and schedulers should be associated with when receiving bandwidth for the queue or schedulers within-cir offered load. The within-cir offered load is the amount of bandwidth the queue or schedulers could use that is equal to or less than its defined or summed CIR value. The summed value is only valid on schedulers and is the sum of the within-cir offered loads of the children attached to the scheduler. The parameters that control within-cir bandwidth allocation for orphans are the orphan-override commands cir-level and cir-weight keywords. The cir-level keyword defines the port priority level that the scheduler or queue uses to receive bandwidth for its within-cir offered load. The cir-weight is used when multiple queues or schedulers exist at the same port priority level for within-cir bandwidth. The weight value defines the relative ratio that is used to distribute bandwidth at the priority level when more within-cir offered load exists than the port priority level has bandwidth.

A cir-weight equal to zero (the default value) has special meaning and informs the system that the orphan queues and schedulers do not receive bandwidth from the within-cir distribution. Instead all bandwidth for the orphan queues and schedulers must be allocated from the port scheduler’s above-cir pass.

Above-CIR Priority Level Parameters

The above-cir parameters define which port priority level the orphan queues and schedulers should be associated with when receiving bandwidth for the queue or schedulers above-cir offered load. The above-cir offered load is the amount of bandwidth the queue or schedulers could use that is equal to or less than its defined PIR value (based on the queue or schedulers rate command) less any bandwidth that was given to the queue or scheduler during the above-cir scheduler pass. The parameters that control above-cir bandwidth allocation for orphans are the orphan-override commands level and weight keywords. The level keyword defines the port priority level that the scheduler or queue uses to receive bandwidth for its above-cir offered load. The weight is used when multiple queues or schedulers exist at the same port priority level for above-cir bandwidth. The weight value defines the relative ratio that is used to distribute bandwidth at the priority level when more above-cir offered load exists than the port priority level has bandwidth.

The no form of the command removes the orphan override port parent association for the orphan queues and schedulers on port schedulers created with the port scheduler policy. Any orphan queues and schedulers on a port associated with the port scheduler policy will revert to default orphan behavior.

Use this command to display scheduler policy information.

This command displays the scheduler hierarchy per customer multi-service-site.

This command displays scheduler hierarchy information per port.

This command displays the scheduler hierarchy per SAP.

This command displays the scheduler hierarchy per subscriber.

This command displays the scheduler policies using the specified scheduler.

This command displays scheduler statistics information.

Display the scheduler stats per SAP.

This command displays scheduler statistics information and applies only to the 7450 ESS and 7750 SR.

This command displays the HQoS aggregate rate limit per customer multi-service-site.

This command displays the HQoS aggregate rate limit per port or vport.

This command displays the HQoS aggregate rate limit per SAP or encap group.

This command displays the HQoS aggregate rate limit per subscriber.

This command displays port-scheduler policy information

This command clears scheduler statistics.