Slope QoS policies

This chapter provides information to configure slope QoS policies using the command line interface.

Overview of buffer pools

Default buffer pool exists (logically) at each port. Buffer pools cannot be created or deleted in the 7210 SAS. The egress buffer pools are created as access uplink port egress buffer pool for access-uplink ports and access port egress buffer pool for access ports. Based on the maximum number of ports to be supported for access and access-uplink, the total buffer is distributed into the access port egress buffer pool and the access uplink port egress buffer pool. The distribution of the buffers into access and access-uplink port egress pools take care of the buffer requirements at the port level for various queue shaping/ scheduling mechanisms and for various packet sizes varying from 64 bytes to jumbo frames. Each port on the system gets an equal portion of the available buffers. From the buffers allocated to a port, each queue gets its CBS amount of buffers. The remaining buffers are allocated toward the shared MBS pool per port. All the queues of the port can use the buffers from the shared MBS pool. By default, each queue on the access port and access-uplink port is associated with slope-policy default which disables the slope parameters within the pool.

On 7210 SAS-D, WRED is supported to evaluate the packet’s eligibility to be allocated a buffer based on the slope parameters configured for the queue.

On 7210 SAS-Dxp, WRED is supported to evaluate the TCP packet’s eligibility to be allocated a buffer based on the slope parameters configured for the queue. WRED is not supported for non-TCP packets.

Configuration guidelines for 7210 SAS-D

7210 SAS-D provides an option to use either 2 slope per queue or 3 slopes per queue. This can be configured using the CLI command config>system>qos>no use-wred-slopes. The option to use only 2 WRED slopes per queue (port egress queues), allows differentiating in-profile and out-of-profile traffic flows. The option to use 3 WRED slopes per queues allows differentiating in-profile TCP traffic, out-of-profile TCP traffic and non-TCP traffic (both in and out-profile use a single slope). The slope does not get enabled by default. To maintain backward compatibility, by default the system uses 3 slopes option and user has to change it explicitly to use 2 slopes (if they need).

The following table compares the WRED slope used for different traffic flows with 2 slopes or 3 slopes per queue.

Table 1. Slope behavior (applicable to 7210 SAS-D)

Slopes

TCP-non-TCP slope option

(uses 3 WRED slopes per queue)

High-low slope option

(uses 2 WRED slopes per queue)

SAP Ingress TCP/IP traffic

(Number of VLAN tags <=2)

High-priority TCP slope or low-priority TCP slope, based on packet profile

High-priority or low-priority slope, based on packet profile

SAP Ingress non-TCP traffic

(Number of VLAN tags does not matter)

Non-TCP slope - No in/out profile differentiation

High-priority or low-priority slope, based on packet profile

SAP Ingress TCP/IP traffic

(Number of VLAN tags>2)

Non-TCP slope - No in/out profile differentiation

High-priority or low-priority slope, based on packet profile

Configuration guidelines for 7210 SAS-Dxp

7210 SAS-Dxp can use two slopes per queue. Using two WRED slopes per queue (port egress queues) allows differentiation of in-profile and out-of-profile TCP traffic flows. The slope is not enabled by default.

Note:

All non-TCP traffic is tail-dropped if the egress queues are full when the traffic is being enqueued.

The following table describes the WRED slope used for different traffic flows with two slopes per queue.

Table 2. Slope behavior (applicable to 7210 SAS-Dxp)

Slopes

High-low slope option

(Uses 2 WRED slopes per queue)

SAP Ingress TCP/IP traffic

(Number of VLAN tags <=2)

High-priority or low-priority slope, based on packet profile

SAP Ingress non-TCP traffic

(Number of VLAN tags does not matter)

Tail-drop

SAP Ingress TCP/IP traffic

(Number of VLAN tags>2)

Tail-drop

Basic configurations

A basic slope QoS policy must conform to the following:

  • Each slope policy must have a unique policy ID.

  • High slope, low slope and non-TCP slope are shut down (default).

  • Default values can be modified but parameters cannot be deleted.

Create a slope QoS policy for 7210 SAS-D

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

To create a new slope policy for 7210 SAS-D devices, define the following:

  • a slope policy ID value

    The system will not dynamically assign a value.

  • include a description

    The description provides a brief overview of policy features.

  • Option to use either 2 slopes per queue or 3 slopes per queue.

  • The high slope for the high priority Random Early Detection (RED) slope graph.

  • The low slope for the low priority Random Early Detection (RED) slope graph.

  • Optional non-TCP slope for the non-TCP Random Early Detection (RED) slope graph.

  • 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 for both 2-slope per queue and 3-slope per queue option. When using 2-slope per queue, the non-tcp slope parameters are not used.

 config>qos
     slope-policy name
         description description-string
         high-slope
             start-avg percent
             max-avg percent                                    
             max-prob percent
             no shutdown
         low-slope
             start-avg percent
             max-avg percent
             max-prob percent
             no shutdown
         non-tcp-slope
             start-avg percent
             max-avg percent
             max-prob percent
             no shutdown
         time-average-factor taf

The following displays the slope policy configuration for 7210 SAS-D:

A:ALA-7>config>qo>slope-policy# info
----------------------------------------------
            description "slope policy SlopePolicy1"
            high-slope
                no shutdown
            exit
            low-slope
                no shutdown
            exit
         non-tcp-slope
             no shutdown
         exit
----------------------------------------------
A:ALA-7>config>qos>slope-policy# 

Create a slope QoS policy for 7210 SAS-Dxp

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

To create a new slope policy for 7210 SAS-Dxp devices, define the following:

  • a slope policy ID value; the system will not dynamically assign a value

  • a description; the description provides a brief overview of policy features

  • two slopes per queue:

    • the high slope for the high priority Random Early Detection (RED) slope graph

    • the low slope for the low priority Random Early Detection (RED) slope graph

  • 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 with two slopes per queue.

 config>qos
     slope-policy name
         description description-string
         high-slope
             start-avg percent
             max-avg percent
             max-prob percent
             no shutdown
         low-slope
             start-avg percent
             max-avg percent
             max-prob percent
             no shutdown
         time-average-factor taf

The following displays the slope policy configuration for 7210 SAS-Dxp:

A:ALA-7>config>qo>slope-policy# info
----------------------------------------------
            description "slope policy SlopePolicy1"
            high-slope
                no shutdown
            exit
            low-slope
                no shutdown
            exit
         exit
----------------------------------------------
A:ALA-7>config>qos>slope-policy# 

Applying slope policies

Based on the 7210 SAS platform capabilities, the slope policies are associated with different entities:

The following CLI syntax examples may be used to apply slope policies to access ports or access-uplink ports.

 config>port>access>egress>pool>slope-policy name
     config>port>access>uplink>egress>pool>slope-policy name

Default slope policy values

This section provides the default values for slope policies.

Default slope values for 7210 SAS-D

The default access egress and access uplink egress policies are identified as policy-id ‟default”. The default policies cannot be edited or deleted. The following table lists default policy parameters.

Table 3. Slope policy defaults for 7210 SAS-D

Field

Default

description

Default slope policy

high (RED) slope

Administrative state

shutdown

start-avg

70% utilization

max-avg

90% utilization

max-prob

75%

low (RED) slope

Administrative state

shutdown

start-avg

50% utilization

max-avg

75% utilization

max-prob

75%

non-TCP (RED) slope

Administrative state

shutdown

start-avg

50% utilization

max-avg

75% utilization

max-prob

75%

A:ALA>config>qos# slope-policy default 
A:ALA>config>qos>slope-policy# info detail 
----------------------------------------------
            description "Default slope policy."
            queue "1" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit                      
            queue "2" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "3" 
                high-slope            
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "4" 
                high-slope
                    shutdown
                    start-avg 70      
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "5" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75       
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "6" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope             
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "7" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50      
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "8" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75       
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
----------------------------------------------
A:ALA>config>qos>slope-policy#

Default slope values for 7210 SAS-Dxp

The default access egress and access uplink egress policies are identified as policy-id ‟default”. The default policies cannot be edited or deleted. The following table lists default policy parameters.

Table 4. Slope policy defaults for 7210 SAS-Dxp

Field

Default

description

Default slope policy

high (RED) slope

Administrative state

shutdown

start-avg

70% utilization

max-avg

90% utilization

max-prob

75%

low (RED) slope

Administrative state

shutdown

start-avg

50% utilization

max-avg

75% utilization

max-prob

75%

A:ALA>config>qos# slope-policy default 
A:ALA>config>qos>slope-policy# info detail 
----------------------------------------------
            description "Default slope policy."
            queue "1" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit                      
            queue "2" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "3" 
                high-slope            
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "4" 
                high-slope
                    shutdown
                    start-avg 70      
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "5" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75       
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "6" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope             
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "7" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50      
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "8" 
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75       
                exit
                time-average-factor 7
            exit
----------------------------------------------
A:ALA>config>qos>slope-policy#

Deleting QoS policies

A slope policy is associated by default with access and access uplink 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 ports where it is applied or if the policies are using the slope-policy.

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

The following CLI syntax examples can be used to remove slope policies from ports.

 config>port>access>egress>pool# no slope-policy name
     config>port>accesss>uplink>egress>pool# no slope-policy name

Remove a policy from the QoS configuration

To delete a slope policy, enter the following command:

 config>qos# no slope-policy policy-id
 config>qos# no slope-policy slopePolicy1

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.

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

The following output displays the copied policies for 7210 SAS-D devices.

A:ALA-7210>config>qos#
----------------------------------------------
...
      description "Default slope policy."
            queue "1"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "2"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "3"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "4"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "5"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "6"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "7"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "8"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                non-tcp-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
...
----------------------------------------------
A:ALA-7210>config>qos#

The following output displays the copied policies for 7210 SAS-Dxp devices.

A:ALA-7210>config>qos#
----------------------------------------------
...
      description "Default slope policy."
            queue "1"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "2"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "3"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "4"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "5"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "6"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "7"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
            queue "8"
                high-slope
                    shutdown
                    start-avg 70
                    max-avg 90
                    max-prob 75
                exit
                low-slope
                    shutdown
                    start-avg 50
                    max-avg 75
                    max-prob 75
                exit
                time-average-factor 7
            exit
...
----------------------------------------------
A:ALA-7210>config>qos#

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, and then write over the original policy.

Slope QoS policy command reference

Command hierarchies

Configuration commands for 7210 SAS-D

    - config
        - qos
            - slope-policy name [create]
            - no slope-policy name
                - description description-string
                - no description 
                - queue queue-id
                    - [no] high-slope
                        - max-avg percent
                        - no max-avg 
                        - max-prob percent
                        - no max-prob
                        - [no] shutdown 
                        - start-avg percent
                        - no start-avg
                    - [no] low-slope
                        - max-avg percent
                        - no max-avg 
                        - max-prob percent
                        - no max-prob 
                        - [no] shutdown 
                        - start-avg percent
                        - no start-avg 
                        - [no] shutdown 
                    - [no] non-tcp-slope
                        - max-avg percent
                        - no max-avg 
                        - max-prob percent
                        - no max-prob
                        - [no] shutdown 
                        - start-avg percent
                        - no start-avg
                    - time-average-factor value
                    - no time-average-factor

Configuration commands for 7210 SAS-Dxp

    - config
        - qos
            - slope-policy name [create]
            - no slope-policy name
                - description description-string
                - no description 
                - queue queue-id
                    - [no] high-slope
                        - max-avg percent
                        - no max-avg 
                        - max-prob percent
                        - no max-prob
                        - [no] shutdown 
                        - start-avg percent
                        - no start-avg
                    - [no] low-slope
                        - max-avg percent
                        - no max-avg 
                        - max-prob percent
                        - no max-prob 
                        - [no] shutdown 
                        - start-avg percent
                        - no start-avg 
                        - [no] shutdown 
                    - time-average-factor value
                    - no time-average-factor

Operational commands

    - config
        - qos
            - copy slope-policy src-name dst-name [overwrite]

Show commands

    - show
        - qos
            - slope-policy [slope-policy-name] [detail]

Command descriptions

Configuration commands

Generic commands

description
Syntax

description description-string

no description

Context

config>qos>slope-policy

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command creates a text description stored in the configuration file for a configuration context.

The description command associates a text string with a configuration context to help identify the context in the configuration file.

The no form of this command removes any description string from the context.

Parameters
description-string

Specifies a text string describing the entity. Allowed values are any string up to 80 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.

copy
Syntax

copy slope-policy src-name dst-name [overwrite]

Context

config>qos

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command copies existing QoS policy entries for a QoS policy-id to another QoS policy-id. It also allows bulk modifications to an existing policy with the use of the overwrite keyword.

Parameters
slope-policy

Specifies that the source policy ID and the destination policy ID are slope policy IDs. Specify the source policy ID that the copy command will attempt to copy from and specify the destination policy ID to which the command will copy a duplicate of the policy.

overwrite

Specifies to replace the existing destination policy. Everything in the existing destination policy will be overwritten with the contents of the source policy. If overwrite is not specified, an error will occur if the destination policy ID exists.

Operational commands

Slope policy QoS commands

slope-policy
Syntax

[no] slope-policy name [create]

Context

config>qos

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This configures a QoS slope policy.

Default

slope-policy ‟default”

Parameters
name

Specifies the name of the slope policy. Valid names consist of any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.

Slope policy QoS policy commands

queue
Syntax

queue queue-id

Context

config>qos>slope-policy

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

Commands in this context configure the high-priority, low-priority, and non-tcp slope parameters per queue.

Parameters
queue-id

Specifies the ID of the queue for which the drop-rate is to be configured.

Values

1 to 8

high-slope
Syntax

[no] high-slope

Context

config>qos>slope-policy>queue

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command defines the high priority RED slope graph. Each buffer pool supports a high priority RED slope for managing access to the shared portion of the buffer pool for high priority or in-profile packets.

The high-slope parameters can be changed at any time and the affected buffer pool high priority RED slopes will be adjusted appropriately.

Note:

See Slope behavior (applicable to 7210 SAS-D) for information about the mapping of traffic types to use high-slope parameters on 7210 SAS-D. See Slope behavior (applicable to 7210 SAS-Dxp) for information about the mapping of traffic types to use high-slope parameters on 7210 SAS-Dxp.

The no form of this command reverts the high slope configuration commands to the default values. If the commands within high-slope are set to the default parameters, the high-slope node will not appear in save config and show config output unless the detail parameter is present.

low-slope
Syntax

[no] low-slope

Context

config>qos>slope-policy>queue

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command defines the low priority RED slope graph. Each buffer pool supports a low priority RED slope for managing access to the shared portion of the buffer pool for low priority or out-of-profile packets.

The low-slope parameters can be changed at any time and the affected buffer pool low priority RED slopes must be adjusted appropriately.

Note:

See Slope behavior (applicable to 7210 SAS-D) for information about the mapping of traffic types to use low-slope parameters on 7210 SAS-D. See Slope behavior (applicable to 7210 SAS-Dxp) for information about the mapping of traffic types to use low-slope parameters on 7210 SAS-Dxp.

The no form of this command reverts the low slope configuration commands to the default values. If the leaf commands within low-slope are set to the default parameters, the low-slope node will not appear in save config and show config output unless the detail parameter is present.

non-tcp-slope
Syntax

[no] non-tcp-slope

Context

config>qos>slope-policy>queue

Platforms

7210 SAS-D

Description

This command configures non-tcp profile RED slope parameters.

Note:

See Slope behavior (applicable to 7210 SAS-D) for information about the mapping of traffic types to use non-TCP-slope parameters on 7210 SAS-D.

The no form of this command reverts to the default.

time-average-factor
Syntax

time-average-factor value

no time-average-factor

Context

config>qos>slope-policy>queue

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures a weighting factor to calculate the new shared buffer average utilization after assigning buffers for a packet entering a queue. To derive the new shared buffer average utilization, the buffer pool takes a portion of the previous shared buffer average and adds it to the inverse portion of the instantaneous shared buffer utilization. The time-average-factor command sets the weighting factor between the old shared buffer average utilization and the current shared buffer instantaneous utilization when calculating the new shared buffer average utilization.

The TAF value applies to all high priority, low priority and non-tcp packets WRED slopes for egress access and network buffer pools controlled by the slope policy.

The no form of this command reverts the default setting.

Default

7

Parameters
value

Specifies the TAF, expressed as a decimal integer. The value specified for TAF affects the speed at which the shared buffer average utilization tracks the instantaneous shared buffer utilization. A low value weights the new shared buffer average utilization calculation more to the shared buffer instantaneous utilization, zero using it exclusively. A high value weights the new shared buffer average utilization calculation more to the previous shared buffer average utilization value.

Values

0 to 15

RED slope commands

max-avg
Syntax

max-avg percent

no max-avg

Context

config>qos>slope-policy>queue>high-slope

config>qos>slope-policy>queue>low-slope

config>qos>slope-policy>queue>non-tcp-slope (supported only on 7210 SAS-D devices)

Platforms

7210 SAS-D, 7210 SAS-Dxp

Description

This command configures the low priority or high priority or non-tcp Weighted Random Early Detection (WRED) slope position for the reserved and shared buffer average utilization value where the packet discard probability rises directly to one. The percent parameter is expressed as a percentage of the shared buffer size.

The no form of this command reverts the value to the default.

Default

max-avg 90 - High slope default is 90% buffer utilization before discard probability is 1

max-avg 75 - Low slope default is 75% buffer utilization before discard probability is 1

max-avg 75 - Non-tcp slope default is 75% buffer utilization before discard probability is 1

Parameters
percent

Specifies the percentage of the reserved and shared buffer space for the buffer pool at which point the drop probability becomes 1. The value entered must be greater or equal to the current setting of startavg. If the entered value is smaller than the current value of start-avg, an error will occur and no change will take place.

Values

0 to 100

max-prob
Syntax

max-prob percent

no max-prob

Context

config>qos>slope-policy>queue>high-slope

config>qos>slope-policy>queue>low-slope

config>qos>slope-policy>queue>non-tcp-slope (supported only on 7210 SAS-D devices)

Platforms

7210 SAS-D, 7210 SAS-Dxp

Description

This command sets the low priority or high priority RED slope position for the maximum non-one packet discard probability value before the packet discard probability rises directly to one. The percent parameter is expressed as a percentage of packet discard probability where always discard is a probability of 1. A max-prob value of 75 represents 75% of 1, or a packet discard probability of 0.75.

The no form of this command reverts the value to the default setting.

Default

max-prob 75

Parameters
percent

Specifies the maximum drop probability percentage corresponding to the max-avg, expressed as a decimal integer.

Values

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 25, 50, 75, 100

shutdown
Syntax

[no] shutdown

Context

config>qos>slope-policy>high-slope

config>qos>slope-policy>low-slope

config>qos>slope-policy>queue

Platforms

7210 SAS-D, 7210 SAS-Dxp

Description

This command enables or disables the administrative status of the RED slope.

By default, all slopes are shutdown and have to be explicitly enabled (no shutdown).

The no form of this command administratively enables the RED slope.

Default

shutdown

start-avg
Syntax

start-avg percent

no start-avg

Context

config>qos>slope-policy>queue>high-slope

config>qos>slope-policy>queue>low-slope

config>qos>slope-policy>queue>non-tcp-slope (supported only on 7210 SAS-D)

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command sets the low priority or high priority RED slope position for the shared buffer average utilization value where the packet discard probability starts to increase above zero. The percent parameter is expressed as a percentage of the shared buffer size.

The no form of this command reverts the value to the default.

Default

max-avg 70 - High slope default is 70% buffer utilization

max-avg 50 - Low slope default is 50% buffer utilization

max-avg 50 - Non-tcp slope default is 50% buffer utilization

Parameters
percent

Specifies the percentage of the reserved and shared buffer space for the buffer pool at which the drop starts. The value entered must be lesser or equal to the current setting of max-avg. If the entered value is greater than the current value of max-avg, an error will occur and no change will take place.

Values

0 to 100

WRED command for 7210 SAS-D

use-wred-slopes
Syntax

use-wred-slopes slope-type

no use-wred-slopes

Context

config>system>qos

Platforms

7210 SAS-D

Description

This command provides the user with the option to use 2 WRED slopes per queue or use 3 WRED slopes per queue. It is a global option which affects all the queues in the system. In other words, user can choose to use either 2 WRED slopes for all queues in the system or 3 WRED slopes for all queues in the system.

Using 3 WRED slopes per queue allows differentiating tcp in-profile traffic, tcp out-of-profile traffic, and non-tcp traffic. For non-tcp traffic both in and out profile use the same slope.

Using 2 WRED slopes per queue allows differentiating in-profile and out-of-profile traffic, without further differentiation of tcp and non-tcp traffic. All traffic, irrespective of tcp or non-tcp traffic, uses either in-profile slope or out-of-profile slope, depending on the profile assigned to the traffic by the ingress meters.

Note:

See Slope behavior (applicable to 7210 SAS-D) for information about the mapping of traffic types to use high-slope, low-slope, and non-TCP-slope parameters on 7210 SAS-D.

The no form of this command enables the use of 3 WRED slopes per queue.

Default

use-wred-slopes tcp-non-tcp to maintain backward compatibility.

Parameters
slope-type

Specifies the slope policy type.

Values

High and Low slope type: When high-low is set, two slopes are used per queue. High priority/In-profile slope for all packets that are classified as in-profile by the ingress meter and Low priority/out-of-profile slope for all packets that are classified as out-of-profile by the ingress meter. The high-priority/in-profile WRED slope uses the values configured under config>qos>slope-policy>high-slope. The low-priority/out-of-profile WRED slope uses the values configured under config>qos>slope-policy>low-slope. The values configured under non-TCP WRED slope is ignored by the system.

TCP and Non-TXP slope type: The non-TCP WRED slope is used for all packets classified as non-TCP packets on ingress, irrespective of the packet's profile or priority. Packets classified as TCP and determined to be high-priority/in-profile by the ingress meter, uses the high priority TCP WRED slope. This slope uses the values configured under config>qos>slope-policy>high-slope. Packets classified as TCP and determined to be low-priority/out-of-profile by the ingress meter, uses the low-priority TCP WRED slope. The low-priority/out-of-profile TCP WRED slope uses the values configured under config>qos>slope-policy>low-slope. The non-TCP WRED slope uses the values configured under config>qos>slope-policy>non-tcp-slope.

Show commands

Show commands

slope-policy
Syntax

slope-policy [slope-policy-name] [detail]

Context

show>qos

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command displays slope policy information.

Parameters
slope-policy-name

Specifies the name of the slope policy.

detail

Displays detailed information about the slope policy.

Output

The following outputs are examples of QoS slope policy information, and the associated tables describe the output fields:

Sample output
*A:>config# show qos slope-policy 1   
===============================================================================
QoS Slope Policy
===============================================================================
Policy         : 1                                                             
-------------------------------------------------------------------------------
Utilization                   State       Start-Threshold
-------------------------------------------------------------------------------
High-Slope                    Down              75%
Low-Slope                     Down              50% 
-------------------------------------------------------------------------------
Queue                   High Slope Drop Rate(%)       Low Slope Drop Rate(%)
-------------------------------------------------------------------------------
Queue 1                        6.250000               100.000000
Queue 2                        6.250000               100.000000
Queue 3                        6.250000               100.000000
Queue 4                        6.250000               100.000000
Queue 5                        6.250000               100.000000
Queue 6                        6.250000               100.000000
Queue 7                        6.250000               100.000000
Queue 8                        6.250000               100.000000
===============================================================================
*A:>config#                           
*A:>config# show qos slope-policy 1 detail 
===============================================================================
QoS Slope Policy
===============================================================================
Policy         : 1                                                             
-------------------------------------------------------------------------------
Utilization                   State       Start-Threshold
-------------------------------------------------------------------------------
High-Slope                    Down              75%
Low-Slope                     Down              50%
-------------------------------------------------------------------------------
Queue                   High Slope Drop Rate(%)       Low Slope Drop Rate(%)
-------------------------------------------------------------------------------
Queue 1                        6.250000               100.000000
Queue 2                        6.250000               100.000000
Queue 3                        6.250000               100.000000
Queue 4                        6.250000               100.000000
Queue 5                        6.250000               100.000000
Queue 6                        6.250000               100.000000
Queue 7                        6.250000               100.000000
Queue 8                        6.250000               100.000000
-------------------------------------------------------------------------------
Associations
-------------------------------------------------------------------------------
Object Type Object Id     Application          Pool
-------------------------------------------------------------------------------
Port        1/1/1         Acc-Egr              default                         
===============================================================================
*A:>config# 
Table 5. Output fields: slope policy

Label

Description

Policy

The ID that uniquely identifies the policy

Description

A string that identifies the policy’s context in the configuration file

Time Avg

The weighting between the previous shared buffer average utilization result and the new shared buffer utilization

Slope Parameters

Start Avg

Specifies the low priority or high priority RED slope position for the shared buffer average utilization value where the packet discard probability starts to increase above zero.

Max Avg

Specifies the percentage of the shared buffer space for the buffer pool at which point the drop probability becomes 1, expressed as a decimal integer

Admin State

Up — The administrative status of the RED slope is enabled

Down — The administrative status of the RED slope is disabled

Specifies the low priority or high priority RED slope position for the maximum non-one packet discard probability value before the packet discard probability rises directly to one.

Max Prob.

Specifies the high priority RED slope position for the maximum non-one packet discard probability value before the packet discard probability rises directly to one.

Sample output: detailed (7210 SAS-D)
*A:SAS-D>show>qos# slope-policy abc detail
===============================================================================
QoS Slope Policy
===============================================================================
Policy         : abc
Description    : (Not Specified)
-------------------------------------------------------------------------------
High Slope
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
QueueId        State      Start-Avg(%)   Max-Avg(%)   Max-Prob(%)
-------------------------------------------------------------------------------
Queue1          Down            70           90            75
Queue2          Down            70           90            75
Queue3          Down            70           90            75
Queue4          Down            70           90            75
Queue5          Down            70           90            75
Queue6          Down            70           90            75
Queue7          Down            70           90            75
Queue8          Down            70           90            75
-------------------------------------------------------------------------------
Low Slope
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
QueueId        State      Start-Avg(%)   Max-Avg(%)   Max-Prob(%)
-------------------------------------------------------------------------------
Queue1          Down            50           75            75
Queue2          Down            50           75            75
Queue3          Down            50           75            75
Queue4          Down            50           75            75
Queue5          Down            50           75            75
Queue6          Down            50           75            75
Queue7          Down            50           75            75
Queue8          Down            50           75            75
-------------------------------------------------------------------------------
Non Tcp Slope
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
QueueId        State      Start-Avg(%)   Max-Avg(%)   Max-Prob(%)
-------------------------------------------------------------------------------
Queue1          Down            50           75            75
Queue2          Down            50           75            75
Queue3          Down            50           75            75
Queue4          Down            50           75            75
Queue5          Down            50           75            75
Queue6          Down            50           75            75
Queue7          Down            50           75            75
Queue8          Down            50           75            75
-------------------------------------------------------------------------------
Time Avg Factor
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Queue Id   Time Avg Factor
-------------------------------------------------------------------------------
Queue1            7
Queue2            7
Queue3            7
Queue4            7
Queue5            7
Queue6            7
Queue7            7
Queue8            7

-------------------------------------------------------------------------------
Associations
-------------------------------------------------------------------------------
Object Type Object Id     Application          Pool
-------------------------------------------------------------------------------
No Matching Entries

*A:SAS-D>show>qos#

*A:SAH01-051>show>qos# slope-policy 32 detail

===============================================================================
QoS Slope Policy
===============================================================================
===============================================================================
*A:SAH01-051>show>qos#
*A:SAH01-051>show>qos# slope-policy 32 detail

===============================================================================
QoS Slope Policy
===============================================================================
===============================================================================
Table 6. Output fields: slope policy detail

Label

Description

Policy

The ID that uniquely identifies the policy

Description

A string that identifies the policy’s context in the configuration file

Time Avg

The weighting between the previous shared buffer average utilization result and the new shared buffer utilization

Slope Parameters

Start Avg

Specifies the low priority or high priority RED slope position for the shared buffer average utilization value where the packet discard probability starts to increase above zero.

Max Avg

Specifies the percentage of the shared buffer space for the buffer pool at which point the drop probability becomes 1, expressed as a decimal integer

Admin State

Up — The administrative status of the RED slope is enabled

Down — The administrative status of the RED slope is disabled

Specifies the low priority or high priority RED slope position for the maximum non-one packet discard probability value before the packet discard probability rises directly to one.

Max Prob.

Specifies the high priority RED slope position for the maximum non-one packet discard probability value before the packet discard probability rises directly to one.