Support For Shared Policy Instance - Cisco ASR 9000 Series Configuration Manual

Support for Shared Policy Instance

dynamic-template type ppp p1
qos account AAL5
service-policy input input_1
end
Support for Shared Policy Instance
Shared Policy Instance (SPI) allows allocation of a single set of QoS resources among groups of BNG
sub-interfaces and bundle sub-interfaces, and shares them across a group of sub-interfaces, multiple Ethernet
flow points (EFPs), or bundle interfaces.
Using SPI, a single instance of QoS policy can be shared across multiple sub-interfaces, allowing for aggregate
shaping of the sub-interfaces to one rate. All sub-interfaces that share the instance of a QoS policy must belong
to the same physical interface. The number of sub-interfaces sharing the QoS policy instance can range from
2 to the maximum number of sub-interfaces on the port.
For bundle interfaces, hardware resources are replicated per bundle member. All sub-interfaces that use a
common shared policy instance and are configured on a Link Aggregation Control Protocol (LAG) bundle
must be load-balanced to the same member link.
When a policy is configured on a bundle EFP, one instance of the policy is configured on each of the bundle
member links. When using SPI across multiple bundle EFPs of the same bundle, one shared instance of the
policy is configured on each of the bundle member links. By default, the bundle load balancing algorithm
uses hashing to distribute the traffic (that needs to be sent out of the bundle EFPs) among its bundle members.
The traffic for single or multiple EFPs can get distributed among multiple bundle members. If multiple EFPs
have traffic that needs to be shaped or policed together using SPI, the bundle load balancing has to be configured
to select the same bundle member (hash-select) for traffic to all the EFPs that belong the same shared instance
of the policy. This ensures that traffic going out on all the EFPs with same shared instance of the policy use
the same policer or shaper Instance.
BNG configures a complete hierarchical policy-map that includes parent and child policies. Optionally, the
SPI name can be defined and attached to the appropriate dynamic template or downloaded from RADIUS, in
this manner:
• Policy configured through a CLI and applied through a dynamic-template
• Policy configured through a CLI and applied through RADIUS
Restrictions
These restrictions apply to the usage of shared policy instance:
• SPI is not supported for subscribers on non-bundle interfaces.
• SPI is not supported for Parameterized QoS (PQoS). In a PQoS configuration, if there exists a SPI name,
• SPI modified through CoA is not supported on subscribers.
Cisco ASR 9000 Series Aggregation Services Router Broadband Network Gateway Configuration Guide,
Release 4.3.x
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mux-1483routed
then it is ignored.
Deploying the Quality of Service (QoS)
OL-28375-03