Slope QoS policies
This chapter provides information to configure slope QoS policies using the command line interface.
Overview of buffer pools and slope policies
For an overview of buffer pools supported on the 7210 SAS-K 2F1C2T, 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C, see Buffer pools.
On the 7210 SAS-K 2F1C2T, slope policies are applied to service ingress queues, service egress queues, access-uplink port ingress queues, and access-uplink port egress queues.
On the 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C, slope policies are applied to service ingress and egress queues; network port ingress and egress queues; hybrid port ingress and egress queues; and access-uplink port ingress and egress queues.
Each of these queuing points allocates buffers from the buffer pool and implements WRED for congestion management. During congestion WRED is used to evaluate how buffers from the pool are allocated to different FCs and to in-profile and out-of-profile traffic within a specific FC. The slope policies define the WRED parameters to use for in-profile/high-priority packets and for out-of-profile/low-priority packets. The high-slope and low-slope define the parameters for in-profile/high-priority packets and for out-of-profile/low-priority packets respectively. In addition, on ring ports the option is available to use separate slopes for ring traffic (that is, traffic coming in on one ring port and going out of another ring port) and non-ring traffic (that is, traffic coming in on access port and going out of another access port or access-uplink port). For more information about ring and non-ring ports, see Buffer pools.
Basic configurations
A basic slope QoS policy must conform to the following:
Each slope policy must have a unique policy ID.
High slope and low slope (both ring and non-ring slopes) are shut down by default.
Default values can be modified but parameters cannot be deleted.
Creating a slope QoS policy
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, define the following:
A slope policy ID value. The system does not dynamically assign a value.
Include a description. The description provides a brief overview of policy features.
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.
Use the following syntax to configure a slope policy.
slope-policy "default" create
description "Default slope policy."
high-slope
shutdown
start-avg percent
max-avg percent
max-prob percent
exit
low-slope
shutdown
start-avg percent
max-avg percent
max-prob percent
exit
high-slope-ring
shutdown
start-avg percent
max-avg percent
max-prob percent
exit
low-slope-ring
shutdown
start-avg percent
max-avg percent
max-prob percent
exitDefault slope policy values for the 7210 SAS-K 2F1C2T, 7210 SAS-K 2F6C4T, and 7210 SAS-K 3SFP+ 8C
The following is a sample default slope policy configuration output, and Default slope policy values lists the default values.
*A:SAH01-051>config>qos>slope-policy$ info detail
----------------------------------------------
no description
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
high-slope-ring
shutdown
start-avg 70
max-avg 90
max-prob 80
exit
low-slope-ring
shutdown
start-avg 50
max-avg 75
max-prob 80
exit
----------------------------------------------
*A:SAH01-051>config>qos>slope-policy$
|
Description |
Default slope policy |
|---|---|
|
high-slope |
|
|
Administrative state |
shutdown |
|
start-avg |
70% utilization |
|
max-avg |
90% utilization |
|
max-prob |
80% |
|
low slope |
|
|
Administrative state |
shutdown |
|
start-threshold |
50% utilization |
|
max-avg |
75% utilization |
|
max-prob |
80% |
|
high-slope-ring |
|
|
Administrative state |
shutdown |
|
start-threshold |
70% utilization |
|
max-avg |
90% utilization |
|
max-prob |
80% |
|
low-slope-ring |
|
|
Administrative state |
shutdown |
|
start-threshold |
50% utilization |
|
max-avg |
75% utilization |
|
max-prob |
80% |
Applying slope policies
On the 7210 SAS-K 2F1C2T, slope policies are associated with service ingress queues, service egress queues, access-uplink port egress queues, and access-uplink port ingress queues.
On the 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C, slope policies are associated with service ingress and egress queues; network port ingress and egress queues; hybrid port ingress and egress queues; and access-uplink port ingress and egress queues.
The following syntax examples may be used to apply slope policies to service ingress queues, service egress queues, access-uplink port ingress queues, and access-uplink port egress queues on the 7210 SAS-K 2F1C2T.
config>qos>sap-ingress> queue id slope-policy name
config>qos>sap-egress> queue id slope-policy name
config>qos>network>ingress> queue id slope-policy name
config>qos>network-queue> queue id slope-policy nameThe following syntax examples may be used to apply slope policies to service ingress and egress queues; network port ingress and egress queues; hybrid port ingress and egress queues; and access-uplink port ingress and egress queues on the 7210 SAS-K 2F6C4T or 7210 SAS-K 3SFP+ 8C.
config>qos>sap-ingress> queue id slope-policy name
config>qos>sap-egress> queue id slope-policy name
config>qos>network>ingress> queue id slope-policy name
config>qos>network-queue> queue id slope-policy nameDeleting 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. 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#Removing slope policies from ports
config>qos>sap-ingress> queue id no slope-policy name
config>qos>sap-egress> queue id no slope-policy name
config>qos>network>ingress> queue id no slope-policy name
config>qos>network-queue> queue id no slope-policy nameRemoving a policy from the QoS configuration
Use the following to delete a slope policy.
config>qos# no slope-policy policy-idconfig>qos# no slope-policy slopePolicy1Copying 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 is a sample output of copied policies.
*A:SAH01-051>config>qos>slope-policy# info detail
----------------------------------------------
description "Default slope policy."
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
high-slope-ring
shutdown
start-avg 70
max-avg 90
max-prob 80
exit
low-slope-ring
shutdown
start-avg 50
max-avg 75
max-prob 80
exit
----------------------------------------------
*A:SAH01-051>config>qos>slope-policy#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
- config
- qos
- slope-policy name [create]
- no slope-policy name
- description description-string
- no description
- [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] high-slope-ring
- max-avg percent
- no max-avg
- max-prob percent
- no max-prob
- [no] shutdown
- start-avg percent
- no start-avg
- [no] low-slope-ring
- max-avg percent
- no max-avg
- max-prob percent
- no max-prob
- [no] shutdown
- start-avg percent
- no start-avg
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.
Slope policy QoS commands
slope-policy
Syntax
slope-policy name [create]
no slope-policy name
Context
config>qos
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command 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 long 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.
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 Random Early Detection (RED) slope graph. A high priority RED slope is used managing access to the shared portion of the buffer pool for high priority or in-profile packets that ingress of non-ring ports and egress out of non-ring ports.
The high-slope parameters can be changed at any time and the affected buffer pool high priority RED slopes are adjusted.
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 mode does 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. A low priority ring RED slope is used managing access to the shared portion of the buffer pool for low priority or out-of-profile packets that are received on non-ring ports and egress out of non-ring ports.
The low-slope parameters can be changed at any time and the affected buffer pool high priority RED slopes are adjusted.
The no form of this command reverts the low slope configuration commands to the default values. If the commands within low-slope are set to the default parameters, the low-slope mode does not appear in save config and show config output unless the detail parameter is present.
high-slope-ring
Syntax
[no] high-slope-ring
Context
config>qos>slope-policy
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command defines the high priority RED slope graph. A high priority ring RED slope is used managing access to the shared portion of the buffer pool for high priority or in-profile packets that ingress of ring ports and egress out of ring ports.
The high-slope-ring parameters can be changed at any time and the affected buffer pool high priority RED slopes are adjusted.
The no form of this command reverts the high slope configuration commands to the default values. If the commands within high-slope-ring are set to the default parameters, the high-slope node does not appear in save config and show config output unless the detail parameter is present.
low-slope-ring
Syntax
[no] low-slope-ring
Context
config>qos>slope-policy
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command defines the low priority Random Early Detection (RED) slope graph. A low priority ring RED slope is used managing access to the shared portion of the buffer pool for low priority or out-of-profile packets that are received on ring ports and egress out of ring ports.
The low-slope-ring parameters can be changed at any time and the affected buffer pool high priority RED slopes are adjusted.
The no form of this command reverts the high slope configuration commands to the default values. If the commands within low-slope-ring are set to the default parameters, the low-slope node does not appear in save config and show config output unless the detail parameter is present.
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>high-slope-ring
config>qos>slope-policy>queue>low-slope-ring
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command sets the low priority or high priority 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 max-avg value to the default setting. If the current startavg setting is larger than the default, an error occurs and the max-avg value is not changed 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 start-avg. If the entered value is smaller than the current value of start-avg, an error occurs and no change takes place.
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>high-slope-ring
config>qos>slope-policy>queue>low-slope-ring
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command sets the low priority or high priority Random Early Detection (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.
Default
max-prob 75
Parameters
- percent
Specifies the maximum drop probability percentage corresponding to the max-avg, expressed as a decimal integer.
shutdown
Syntax
[no] shutdown
Context
config>qos>slope-policy>high-slope
config>qos>slope-policy>low-slope
config>qos>slope-policy>queue>high-slope-ring
config>qos>slope-policy>queue>low-slope-ring
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command enables or disables the administrative status of the Random Early Detection 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>high-slope-ring
config>qos>slope-policy>queue>low-slope-ring
Platforms
Supported on all 7210 SAS platforms as described in this document
Description
This command sets the low priority or high priority Random Early Detection (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. If the max-avg setting is smaller than the default, an error occurs and the start-avg setting is not changed 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 occurs and no change takes place.
Operational commands
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.
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.
Parameters
- slope-policy src-name dst-name
Specifies the source policy ID that the copy command attempts to copy from and specifies the destination policy ID to which the command copies a duplicate of the policy. This parameter indicates that the source policy ID and the destination policy ID are slope policy IDs.
- overwrite
Keyword to replace the existing destination policy. Everything in the existing destination policy is overwritten with the contents of the source policy. If overwrite is not specified, an error occurs if the destination policy ID exists.
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 output is an example of QoS slope policy information, and Output fields: QoS slope policy describes the output fields.
Sample output*A:SAH01-051>show>qos# slope-policy "default"
===============================================================================
QoS Slope Policy
===============================================================================
Policy : default
Description : Default slope policy.
-------------------------------------------------------------------------------
High Slope Parameters
-------------------------------------------------------------------------------
Start Avg : 70 Admin State : Disabled
Max Avg : 90 Max Prob. : 80
-------------------------------------------------------------------------------
Low Slope Parameters
-------------------------------------------------------------------------------
Start Avg : 50 Admin State : Disabled
Max Avg : 75 Max Prob. : 80
-------------------------------------------------------------------------------
High Slope Ring Parameters
-------------------------------------------------------------------------------
Start Avg : 70 Admin State : Disabled
Max Avg : 90 Max Prob. : 80
-------------------------------------------------------------------------------
Low Slope Ring Parameters
-------------------------------------------------------------------------------
Start Avg : 50 Admin State : Disabled
Max Avg : 75 Max Prob. : 80
===============================================================================
*A:SAH01-051>show>qos#
*A:SAH01-051>show>qos# slope-policy detail
===============================================================================
QoS Slope Policy
===============================================================================
Policy : default
Description : Default slope policy.
-------------------------------------------------------------------------------
High Slope Parameters
-------------------------------------------------------------------------------
Start Avg : 70 Admin State : Disabled
Max Avg : 90 Max Prob. : 80
-------------------------------------------------------------------------------
Low Slope Parameters
-------------------------------------------------------------------------------
Start Avg : 50 Admin State : Disabled
Max Avg : 75 Max Prob. : 80
-------------------------------------------------------------------------------
High Slope Ring Parameters
-------------------------------------------------------------------------------
Start Avg : 70 Admin State : Disabled
Max Avg : 90 Max Prob. : 80
-------------------------------------------------------------------------------
Low Slope Ring Parameters
-------------------------------------------------------------------------------
Start Avg : 50 Admin State : Disabled
Max Avg : 75 Max Prob. : 80
-------------------------------------------------------------------------------
SAP Ingress
-------------------------------------------------------------------------------
SAP Ingress Policy Id : 1
Queue Ids : 1
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
SAP Egress
-------------------------------------------------------------------------------
SAP Egress Policy Id : 1
Queue Ids : 1
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Network Ingress
------------------------------------------------------------------------------
Network Ingress Policy Id : 1
Queue Ids : 1, 2, 3, 4, 5, 6, 7, 8
------------------------------------------------------------------------------
Network Queues
------------------------------------------------------------------------------
Network Queue Policy Name : default
Queue Ids : 1, 2, 3, 4, 5, 6, 7, 8
------------------------------------------------------------------------------
==============================================================================
*A:SAH01-051>show>qos#
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 |