This chapter provides information to configure slope QoS policies using the command line interface.
Topics in this chapter include:
Random Early Detection (RED) and Weighted Random Early Detection (WRED) queue management policies are associated with queues and can be created at both access and network ports and in both directions (that is, ingress and egress). The main difference is that with WRED, there can be more than one slope curve managing the fill rate of the same queue. One curve manages the discards on high-priority traffic, and another curve manages the discards on low-priority traffic. For more information, refer to Slope Policies (WRED and RED).
On all adapter cards and platforms except the Gen-3 Ethernet adapter cards and platforms (such as the 6-port Ethernet 10Gbps Adapter card and the 7705 SAR-X with Ethernet ports), random discards (WRED) are buffer-based (that is, buffer-count in the queue is used to calculate the discard threshold). On the Gen-3 Ethernet adapter cards and platforms, random discards are byte-based (that is, payload-count (bytes) in the queue is used to calculate the discard threshold). The 7705 SAR-X with a TDM MDA uses buffer-based WRED.
For information about the tasks and commands necessary to access the command line interface and to configure and maintain the 7705 SAR, refer to the 7705 SAR Basic System Configuration Guide, “CLI Usage”.
This section contains the following topics related to creating and applying slope QoS policies:
A basic slope QoS policy must conform to the following rules.
Configuring and applying QoS policies is optional. If no QoS policy is explicitly defined, a default QoS policy is applied.
To create a new slope policy, you must define the following:
Use the following CLI syntax to configure a slope policy:
The following output shows the configuration for SlopePolicy1:
Slope policies are applied to network and access egress and ingress queues.
Use the following CLI syntax:
The default slope policies are identified as default. The default policies cannot be edited or deleted. Table 50 displays the default slope policy parameters.
Field | Default |
description | “Default slope policy” |
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 |
The following output displays the default configuration:
This section describes the following service management tasks:
A QoS policy cannot be deleted until it is removed from a network or access egress/ingress queue. Use the following CLI syntax:
Use the following CLI syntax to delete a slope policy:
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.
Use the following syntax to overwrite an existing QoS slope policy.
The following output displays the copied policies:
You can change existing policies and entries in the CLI. The changes are applied immediately to all queues 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.