Shaper QoS Policies
In This Chapter
This chapter provides information to configure shaper QoS policies using the command line interface.
Topics in this chapter include:
Overview
Shaper policies are used to configure dual-rate shapers that control access or network traffic flows through the 7705 SAR. The dual-rate shapers provide a third tier of aggregate shaping to shaped and unshaped SAP traffic for access egress flows and to shaped and unshaped VLAN traffic for network egress flows. See QoS for Hybrid Ports for more information.
Configuring a dual-rate aggregate shaper means setting PIR and CIR values, which is done through an entity called a shaper group.
On a hybrid port, both access and network traffic share the same physical port. The shaper policy is applied independently to the access egress or network egress traffic.
 | Note:
In Release 7.0, the only shaper group supported is the default shaper group. |
Basic Configuration
This section contains the following topics related to creating and applying shaper QoS policies:
A basic shaper QoS policy must conform to the following rules.
- Each shaper policy must have a unique policy identifier (name).
- Default values can be modified but parameters cannot be deleted.
Creating a Shaper QoS Policy
Configuring and applying shaper QoS policies is optional. If no shaper QoS policy is explicitly defined, the default shaper QoS policy (“default”) is applied.
To create a new shaper policy, define the following:
- a shaper policy name — the system does not dynamically assign a name
- a description (optional) — a brief description of the policy
- a shaper group (optional) and its PIR and CIR values — a shaper group is an access or a network aggregate dual-rate shaper (see QoS for Hybrid Ports) and per-customer shapers
Use the following CLI syntax to configure a shaper policy:
The following sample output shows the configuration for “shaper_policy_2”:
Applying a Shaper Policy
A shaper policy must be assigned to an Ethernet MDA for access ingress per-customer aggregate shaping or to a port for access egress per-customer aggregate shaping. Shaper groups created within the shaper policy provide the per-customer aggregate shapers. The unshaped SAP shaper group within the policy provides the shaper rate for all the unshaped SAPs (4-priority scheduled SAPs). For each shaped SAP, however, an ingress or egress shaper group can be specified.
For ingress, the shaper group assigned to a SAP or unshaped shaper group must be a shaper group from the shaper policy assigned to the Ethernet MDA. For egress, the shaper group assigned to a SAP or unshaped shaper group must be a shaper group from the shaper policy assigned to the port. All ingress shaped or unshaped SAPs configured with the same ingress shaper group on an Ethernet MDA have their aggregate traffic shaped at the shaper group rate. Similarly, all the egress shaped or unshaped SAPs configured with the same egress shaper group on a port have their aggregate traffic shaped at the shaper group rate.
On all non-chassis based 7705 SAR variants, 7705 SAR-A, 7705 SAR-H, 7705 SAR-Hc, 7705 SAR-M, 7705 SAR-W, 7705 SAR-Wx (excluding 7705 SAR-X), when a shaper policy is assigned to an Ethernet MDA for access ingress aggregate shaping, it is automatically assigned to all the Ethernet MDAs in that chassis. The shaper group members contained in the shaper policy span all the Ethernet MDAs. SAPs on different Ethernet MDAs configured with the same ingress shaper group will share the shaper group rate.
For hybrid ports, one shaper policy can be applied to the network egress traffic as well as to the access egress traffic. For network egress, all the shaped interfaces (VLANs) and unshaped interfaces are bound to the default shaper group contained in the shaper policy assigned to the network egress port. The access egress traffic is bound to the shaper group assigned to each shaped SAP or to the default shaper group if none is assigned, and all the unshaped SAPs are assigned to the unshaped shaper group or to the default shaper group if none is assigned. Traffic is then scheduled between the network and access shaper groups by ensuring that the CIR rate for each shaper group is scheduled before any of the excess information rate (EIR) traffic from any of the shaper groups.
| Note:
|
Use the following CLI syntax to apply a shaper policy to a hybrid port (access and network egress).
The following sample output shows different shaper policies applied to access egress and network egress traffic on a hybrid port:
Default Shaper Policy Values
The default shaper policies are identified by the policy name “default”. The default policies cannot be deleted. Table 63 displays the default shaper policy parameters.
Table 63: Shaper Policy Defaults
Field | Default |
description | “Default Shaper QoS policy.” |
shaper-group | “default” |
description | “Default Shaper Group.” |
pir-rate | max |
cir-rate | 0 |
The following sample output displays the default configuration:
Configuring Per-SAP Aggregate Shapers
Per-SAP aggregate shapers can be configured for the following services: Epipe, Ipipe, IES, VPLS, and VPRN. Refer to the 7705 SAR OS Services Guide for command descriptions.
Use the following CLI syntax to configure an Epipe per-SAP aggregate shaper (Ipipe and VPLS syntax is similar):
Use the following CLI syntax to configure an IES per-SAP aggregate shaper (VPRN syntax is similar):
Configuring a CIR for Access Egress Unshaped SAPs
To provide arbitration between the bulk (aggregate) of unshaped SAPs and the shaped SAPs, assign a rate to the unshaped SAPs. Refer to the 7705 SAR OS Interface Configuration Guide for command descriptions.
Use the following CLI syntax to configure a CIR for the bulk of access egress unshaped SAPs:
Configuring Per-VLAN Network Egress Shapers
Per-VLAN network egress shapers can be configured for network interfaces. Refer to the 7705 SAR OS Router Configuration Guide for command descriptions.
The queue-policy command is used to enable and disable the network egress per-VLAN shapers on a per-interface basis. If the no queue-policy command is used, the VLAN (that is, the interface) defaults to unshaped mode. Note that the agg-rate-limit command cannot be accessed unless a network queue policy is assigned to the interface.
Use the following CLI syntax to configure a per-VLAN network egress shaper on a network interface:
Configuring a CIR for Network Egress Unshaped VLANs
To provide arbitration between the bulk (aggregate) of unshaped VLANs and the shaped VLANs, assign a rate to the unshaped VLANs. Refer to the 7705 SAR OS Interface Configuration Guide for command descriptions.
Use the following CLI syntax to configure a CIR for the bulk of network egress unshaped VLANs:
Service Management Tasks
This section describes the following service management tasks:
Removing and Deleting QoS Policies
A QoS policy cannot be deleted until its associations with all the ports are removed.
Since one shaper policy can be assigned to multiple ports, you must remove all the associations to the ports before deleting the shaper policy.
Use the following CLI syntax to remove a shaper policy from a port and then delete the shaper policy from the QoS configuration:
Copying and Overwriting QoS Policies
You can copy an existing shaper policy to a new shaper policy or overwrite an existing shaper policy. If the destination policy ID exists, the overwrite option must be specified or an error occurs.
Use the following syntax to overwrite an existing shaper QoS policy.
The following sample output displays the copied policies:
Editing QoS 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.