8.  Slope QoS Policies

8.1. In This Section

This section provides information about configuring slope QoS policies using the CLI.

Topics in this section include:

8.2. Overview

Default buffer pools exist (logically) at the port, FP or MDA and node levels. Each physical port has three associated pool objects:

  1. Access ingress pool
  2. Access egress pool
  3. Network egress pool

Each MDA on FP1 hardware has four associated pool objects:

  1. Access egress pool
  2. Access ingress pool
  3. Acc-Ing MC Path Mgmt
  4. Network egress pool

Each FP on FP2 or higher based hardware has five associated pool objects:

  1. Access egress pool
  2. Access ingress pool
  3. Acc-Ing MC Path Mgmt
  4. Network ingress pool
  5. Network egress pool

By default, each pool is associated with slope-policy default, which has the slopes within the pool shutdown.

Slope policies are also applied when WRED is applied per queue and to the associated megapools, see WRED Per Queue.

8.3. Basic Configurations

A basic slope QoS policy must conform to the following:

  1. Each slope policy must have a unique policy ID.
  2. Highplus slope, high slope, low slope, and exceed slope must be shut down (default).
  3. Default values can be modified but parameters cannot be deleted.

8.3.1. Creating a Slope QoS Policy

Configuring and applying slope policies is optional. If no slope policy is explicitly applied to a pool, a default slope policy is applied.

To create a new slope policy, define the following:

  1. A slope policy ID value. The system will not dynamically assign a value.
  2. Include a description. The description provides a brief overview of policy features.
  3. The highplus slope for the highplus Random Early Detection (RED) slope graph.
  4. The high slope for the high Random Early Detection (RED) slope graph.
  5. The low slope for the low Random Early Detection (RED) slope graph.
  6. The exceed slope for the exceed Random Early Detection (RED) slope graph.
  7. The time average factor (TAF), a weighting exponent used to determine the portion of the shared buffer instantaneous utilization and shared buffer average utilization used to calculate the new shared buffer average utilization.

Use the following CLI syntax to configure a slope policy:

CLI Syntax:
config>qos#
slope-policy name [create]
description description-string
exceed-slope
max-avg percent
max-prob percent
start-avg percent
no shutdown
high-slope
max-avg percent
max-prob percent
start-avg percent
no shutdown
highplus-slope
max-avg percent
max-prob percent
start-avg percent
no shutdown
low-slope
max-avg percent
max-prob percent
start-avg percent
no shutdown
time-average-factor value

The following displays the slope policy configuration:

A:ALA-7>config>qos# info
#------------------------------------------
echo "QoS Slope/Queue Policies Configuration"
#------------------------------------------
...
        slope-policy "slopePolicy1" create
            description "Test"
            highplus-slope
                no shutdown
            exit
            high-slope
                no shutdown
            exit
            low-slope
                no shutdown
            exit
            exceed-slope
                no shutdown
            exit
        exit
...
#------------------------------------------
A:ALA-7>config>qos# 

8.3.2. Applying Slope Policies

Apply slope policies to the following entities:

8.3.2.1. Ports

The following CLI syntax examples may be used to apply slope policies to port pools:

CLI Syntax:
config>port>access>ingress>pool>slope-policy name
config>port>access>egress>pool>slope-policy name
config>port>network>egress>pool>slope-policy name

8.3.2.2. MDA (FP1)

The following CLI syntax examples may be used to apply slope policies to MDA pools:

CLI Syntax:
config>card>mda>access>ingress>pool>slope-policy name
config>card>mda>access>egress>pool>slope-policy name
config>card>mda>network>egress>pool>slope-policy name

For the MC Path Mgmt, the slope policy is configured within a multicast management bandwidth policy that is then applied under the MDA ingress multicast-path-management.

CLI Syntax:
config>mcast-mgmt>bw-plcy> mcast-pool percent-of-total <percent-of-buffers> resv-cbs <percent-of-pool> slope-policy <policy-name>
config>card>mda>ingress>mcast-mgmt# bandwidth-policy <policy-name>

The following CLI syntax example configures the PPP multilink pool:

CLI Syntax:
config>card>mda>access>egress>pool>slope-policy name

8.3.2.3. FP (FP2 and higher based hardware)

The following CLI syntax examples may be used to apply slope policies to FP pools:

CLI Syntax:
config>card>mda>access>ingress>pool>slope-policy name
config>card>mda>access>egress>pool>slope-policy name
config>card>mda>network>ingress>pool>slope-policy name
config>card>mda>network>egress>pool>slope-policy name

Although these commands are applied under the MDA CLI tree, the policy is applied to the FP. If different policies are applied to each MDA, the last policy applied take precedence.

For the MC Path Mgmt, the slope policy is configured within a multicast management bandwidth policy that is then applied under the FP ingress multicast-path-management.

CLI Syntax:
config>mcast-mgmt>bw-plcy> mcast-pool percent-of-total <percent-of-buffers> resv-cbs <percent-of-pool> slope-policy <policy-name>

8.3.3. Default Slope Policy Values

The default access ingress and egress policies are identified as policy-id 1. The default policies cannot be edited or deleted. Table 82 displays default policy parameters.

Table 82:  Slope Policy Defaults  

Parameter

Default

Description

“Default slope policy”

Highplus-slope

shutdown

shutdown

start-avg

85

max-avg

100

max-prob

80

High-slope

shutdown

shutdown

start-avg

70

max-avg

90

max-prob

80

Low-slope

shutdown

shutdown

start-avg

50

max-avg

75

max-prob

80

Exceed-slope

shutdown

shutdown

start-avg

30

max-avg

55

max-prob

80

Time-average-factor

7

The following output displays the default configuration:

A:ALA-7>config>qos>slope-policy# info detail
----------------------------------------------
            description "Default slope policy."
            highplus-slope
                shutdown
                start-avg 85
                max-avg 100
                max-prob 80
            exit
            high-slope
                shutdown
                start-avg 70
                max-avg 90
                max-prob 80
            exit
            low-slope
                shutdown
                start-avg 50
                max-avg 75
                max-prob 80
            exit
            exceed-slope
                shutdown
                start-avg 30
                max-avg 55
                max-prob 80
            exit
 time-average-factor 7
----------------------------------------------
A:ALA-7>config>qos>slope-policy#

8.4. Service Management Tasks

This section discusses the following service management tasks:

8.4.1. Deleting QoS Policies

A slope policy is associated by default with XMAs and MDAs and port access and network egress pools. A default policy may be replaced with a non-default policy, but a policy cannot be entirely removed from the configuration. When a non-default policy is removed, the policy association reverts to the default slope policy policy-id default. A QoS policy cannot be deleted until it is removed from all of the places where it is applied.

A:ALA-7>config>qos# no slope-policy slopePolicy1
MINOR: QOS #1902 Slope policy has references
A:ALA-7>config>qos#

8.4.1.1. Ports

The following CLI syntax examples can be used to remove slope policies from port pools:

CLI Syntax:
config>port>access>ingress>pool# no slope-policy name
config>port>access>egress>pool# no slope-policy name
config>port>network>egress>pool# no slope-policy name

8.4.1.2. MDA (FP1)

The following CLI syntax examples can be used to remove slope policies from MDAs:

CLI Syntax:
config>card>mda>access>ingress>pool# no slope-policy name
config>card>mda>access>egress>pool# no slope-policy name
config>card>mda>network>egress>pool# no slope-policy name

For the MC Path Mgmt, the mcast-pool can be removed from the bandwidth policy or the bandwidth-policy can be removed from under the MDA ingress multicast-path-management.

CLI Syntax:
config>mcast-mgmt>bw-plcy# no mcast-pool
config>card>mda>ingress>mcast-mgmt# no bandwidth-policy

The following CLI syntax example configures the PPP multilink pool:

CLI Syntax:
config>card>mda>access>egress>pool# no slope-policy name

8.4.1.3. FP (FP2 and higher based hardware)

The following CLI syntax examples can be used to remove slope policies from FP pools:

CLI Syntax:
config>card>mda>access>ingress>pool# no slope-policy name
config>card>mda>access>egress>pool# no slope-policy name
config>card>mda>network>ingress>pool# no slope-policy name
config>card>mda>network>egress>pool# no slope-policy name

Although some commands are applied under the MDA CLI tree, the policy is applied to the FP. If different policies are applied to each MDA, the last policy applied take precedence.

For the MC Path Mgmt, the mcast-pool can be removed from the bandwidth policy or the bandwidth-policy can be removed from under the FP ingress multicast-path-management.

CLI Syntax:
config>mcast-mgmt>bw-plcy# no mcast-pool
config>card>fp>ingress>mcast-mgmt# no bandwidth-policy

8.4.1.4. Removing a Policy from the QoS Configuration

To delete a slope policy, enter the following command:

CLI Syntax:
config>qos# no slope-policy policy-id
Example:
config>qos# no slope-policy slopePolicy1

8.4.2. Copying and Overwriting QoS Policies

You can copy an existing slope policy, rename it with a new policy ID value, or overwrite an existing policy ID. The overwrite option must be specified or an error occurs if the destination policy ID exists.

CLI Syntax:
config>qos> copy {slope-policy} source-policy-id dest-policy-id [overwrite]

8.4.3. Editing QoS Policies

You can change existing policies and entries in the CLI or NMS. The changes are applied immediately to all services where this policy is applied. To prevent configuration errors copy the policy to a work area, make the edits, then write over the original policy.