Cisco ASR 9000 Series Configuration Manual page 219

Deploying the Quality of Service (QoS)
S-VLAN Shaping and Statistics
In the egress direction, the BNG supports the ability to have policies at three different levels: the subscriber
interface level, the stacked virtual local area network (S-VLAN), and at the port level. The egress S-VLAN
and port-level policies are applied through CLI directly at the interface level. For applying a QoS policy on
S-VLAN, see
The subscriber policy can only be applied through a dynamic template or via RADIUS. The egress subscriber
policy can be a two-level policy. The S-VLAN and port-level policies can only be flat policies, with only the
class default, with the only action being a shaped rate. Essentially it provides a means to constrain the S-VLAN
or port to a maximum rate via shaping.
In the ingress direction, the traffic is only subject to the subscriber input policy where the subscriber policies
are applied through RADIUS or dynamic-template.
The traffic through the S-VLAN includes traffic to many subscribers that may have already been shaped by
the subscriber policies. Providing statistics on that S-VLAN shaper is important in order to monitor whether
it is reaching the maximum capacity. Unlike the subscriber QoS policies, the HW does not have the ability
to directly track the usage or transmitted packets/bytes through this S-VLAN shaper. So unlike other statistics,
the BNG provides the S-VLAN QoS policy-related statistics by aggregating the statistics of the underlying
subscriber policies. The statistics are displayed via show commands (and MIBs as appropriate) consistent
with all other interface types.
S-VLAN supports these conditions:
• Modification of QoS rates.
• Modification of S-VLAN policy to change number of levels in the policy is rejected.
• Modification of two-level S-VLAN policy to add or remove child-level classes is rejected.
• Modification of classification criteria in child-level classes, in two-level policy, is rejected.
• Addition or removal of actions, in both two-level and flat policy, is rejected.
QoS Attachment Points
This table lists the QoS attachment points, and modes for definition and application.
QoS Attachment Point
Port (sub-rate policy)
S-VLAN
Subscriber
OL-28375-03
Configuring Policy on S-VLAN, on page 209
Definition
CLI/XML
CLI/XML
CLI/XML
Cisco ASR 9000 Series Aggregation Services Router Broadband Network Gateway Configuration Guide, Release
QoS Features Supported on BNG
Application Type of Policy
CLI/XML Flat – class-default
only
CLI/XML Flat – class-default
only. 2 level, with
parent class-default
only and child any
classification.
Dynamic-Template 2 level, with parent
class-default only and
child any
classification.
4.3.x
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