Modification Of A Vlan-Group Policy Map; Vlan-Group Policies And Inheritance; Aggregate Session Traffic - Cisco 10000 Series Configuration Manual

Chapter 21 VLAN Tag-Based Quality of Service

Modification of a VLAN-Group Policy Map

For example, consider the following sample configuration:
policy-map Input_Parent
Adding or removing VLAN-group classes from a VLAN-group policy only affects QoS on the
subinterfaces that you added or removed from the policy. Adding or removing class-default classes
affects QoS only on the subinterfaces that do not belong to any VLAN group.
Modifying a child policy that is applied to a VLAN-group class in a VLAN-group policy affects QoS on
all of the subinterfaces that belong to that VLAN group. Modifying a child policy applied to a
class-default class affects QoS on all of the subinterfaces that do not belong to any VLAN group.
For more information, see the
VLAN ID
The VLAN ID is a number you specify to identify a VLAN subinterface. The router uses the VLAN ID
of packets to classify them as belonging to specific VLAN groups. Valid VLAN ID values are from 1 to
4094.

VLAN-Group Policies and Inheritance

Note
For non-VLAN-group QoS policies, the PRE3 supports the configuration of shaping only at the
subinterface level and a hierarchical queuing policy at the virtual template level. In this case, the PPP
session traffic uniquely inherits the policy on the virtual template and the aggregate of all of the PPP
session traffic is also shaped by the subinterface policy.
All subinterfaces that are not part of a VLAN group and that do not have a service policy attached inherit
For an output parent policy, the PRE2 allows you to configure only the shape command on the
•
the policy applied on the class-default class of a VLAN-group policy.
parent class. The PRE3 allows you to configure the shape command and the bandwidth remaining
For sessions terminated on a subinterface that is part of a VLAN-group policy, the following occurs:
ratio command on the parent class. The bandwidth remaining ratio command allows you to define
a proportionate share of the bandwidth for allocation to VLAN groups during periods of congestion.
•
For example, the following sample configuration shows how to configure an output parent policy:
policy-map Egress_Parent
•
For input policies, if you apply a child QoS policy to a VLAN-group traffic class (created using the
•

Aggregate Session Traffic

match-vlan command in a class map), you must first configure a policing action. The router
supports non-queuing actions (policing) for input policies, and both queuing (shaping) and
You cannot shape the aggregate session traffic by applying a shaping policy to a VLAN group. Instead,
non-queuing (policing) actions for output policies.
when applying queuing policies to sessions, shape the aggregate session traffic by applying a shaping
• If you attach a VLAN-group policy in the outbound direction, configure a shaper for each VLAN
policy to an 802.1Q VLAN or QinQ subinterface. For more information, see the QoS: Hierarchical
group so that the group has its own VTMS link. Otherwise, the traffic for that VLAN group uses the
Queuing for Ethernet DSLAMs feature module for Cisco IOS Release 12.2(31)SB2.
VTMS link and queues of the main interface.
Although you cannot shape PPP sessions, you can police the sessions.
For VLAN-based classes with multiple VLAN match filters defined, traffic accounting is updated
•
as an aggregate under the first match-VLAN filter for the class in the policy. The router does not
maintain individual match-VLAN filter statistics.
OL-7433-09
class vlangrp1
police percent 10
service-policy Child1
class vlangrp2
police percent 30
class vlangrp3
shape 512000
service-policy Child2
class vlangrp4
police 8000
service-policy Child3
– The class vlangrp1 is a valid configuration for input traffic because it has a non-queuing action
(policing) defined before the Child1 service policy is applied.
The class vlangrp2 is a valid configuration because non-queuing actions are permitted for input
–
policies.
The class vlangrp3 is an invalid configuration for this input parent policy because it contains a
–
queuing action (shape).
If this was an output parent policy, the class vlangrp3 would be a valid configuration because
queuing actions such as shape are permitted for output policies.
The class vlangrp4 is a valid configuration for an input parent policy because it contains a
–
non-queuing action (police) before applying the child service policy.
If the virtual template applied to the subinterface does not have a QoS policy (non-VLAN-group),
the virtual access interface (VAI) that is created when PPP session creation occurs does not uniquely
inherit the policy inherited by the subinterface. For example, suppose a subinterface policy shapes
traffic to 2 Mbps and two PPPoE sessions initiate. The total traffic from both of the PPPoE sessions
class vgrp1
is aggregately shaped to 2 Mbps. Each PPP session traffic is not shaped uniquely to 2 Mbps.
shape 128000
service-policy Child3
If the virtual template applied to the subinterface has a QoS policy (for example, a non-queuing
class vgrp2
policy that specifies policing and marking for the PRE2 or all QoS actions for the PRE3), each PPP
shape 512000
session traffic is uniquely influenced by the policy defined at the virtual template. For example,
service-policy Child2
suppose a hierarchical QoS policy is configured to police traffic to 2 Mbps. Each PPPoE session
class class-default
traffic is uniquely policed to 2 Mbps. The policy on the subinterface has no affect.
shape 2000000
service-policy Child1
"VLAN Tag-Based QoS" section on page
Cisco 10000 Series Router Quality of Service Configuration Guide
VLAN Tag-Based QoS
21-1,
21-3