Slope QoS policies
Overview
Default buffer pools exist (logically) at the port, FP or MDA, and node levels. Each physical port has three associated pool objects:
access ingress pool
access egress pool
network egress pool
Each FP has five associated pool objects:
access egress pool
access ingress pool
Acc-Ing MC path management
network ingress pool
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.
Basic configurations
A basic slope QoS policy must conform to the following:
Each slope policy must have a unique policy ID.
Highplus slope, high slope, low slope, and exceed slope must be shut down (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 pool, 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.
a description. The description provides a brief overview of policy features.
the highplus slope for the highplus Random Early Detection (RED) slope graph
the high slope for the high Random Early Detection (RED) slope graph
the low slope for the low Random Early Detection (RED) slope graph
the exceed slope for the exceed 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
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#
Applying slope policies
Apply slope policies to the following entities:
Ports
The following CLI syntax examples may be used to apply slope policies to port pools:
config>port>access>ingress>pool>slope-policy name
config>port>access>egress>pool>slope-policy name
config>port>network>egress>pool>slope-policy name
FP
The following CLI syntax examples may be used to apply slope policies to FP ingress network pools:
config>card>fp>ingress>network>pool>slope-policy name
For multicast path management, the slope policy is configured within a multicast management bandwidth policy that is then applied under the FP ingress multicast-path-management.
config>mcast-mgmt>bw-plcy>mcast-pool percent-of-total <percent-of-buffers> resv-cbs <percent-of-pool> slope-policy <policy-name>
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. Slope policy defaults lists default policy parameters.
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#
Service management tasks
This section discusses slope QoS policy service management tasks:
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#
Ports
The following CLI syntax examples can be used to remove slope policies from port pools:
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
FP
The following CLI syntax examples may be used to apply slope policies to FP ingress network pools:
config>card>fp>ingress>network>pool>slope-policy name
For multicast path management, the slope policy is configured within a multicast management bandwidth policy that is then applied under the FP ingress multicast-path-management.
config>mcast-mgmt>bw-plcy>mcast-pool percent-of-total <percent-of-buffers> resv-cbs <percent-of-pool> slope-policy <policy-name>
Removing a policy from the QoS configuration
To delete a slope policy, enter the following command:
config>qos# no slope-policy policy-id
Example:
config>qos# no slope-policy slopePolicy1
Copying and overwriting QoS policies
An existing slope policy can be copied, renamed with a new policy ID value, or used to 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]
Editing QoS policies
Existing policies and entries in the CLI or NMS can be edited. 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.