Cisco 10000 Series User Manual

18-3
Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 18 Regulating and Shaping Subscriber Traffic
Subscriber-Based IP Quality of Service
Per Session Rate Limiting
The per session rate limiting feature is a traffic regulation mechanism that allows you to control the
maximum rate of traffic sent or received on an interface for a session. The feature is configured on
interfaces at the edge of a network to limit traffic into or out of the network. The rate limiting feature
uses the modular QoS CLI to provide input and output policing rates for each session.
The Cisco 10000 series router uses policing to manage the access bandwidth policy for the following
subscriber-based sessions:
• PPPoA
• PPPoE
• PPP in L2TP (LNS only)
• RBE
The configuration of per session rate limiting involves the following components:
• Class map—Classifies the traffic on an interface. The class map uses the match statements that you
define to classify subscriber traffic.
• Policy map—Defines QoS actions and rules and associates these to a class map. The policy map
specifies the class map for a session and also indicates the policing actions to perform.
• Service policy—Attaches a policy map to an interface and specifies the direction (inbound or
outbound) that the policy should be applied.
QoS configuration typically involves applying the service policies to interfaces. For PPPoA, PPPoE, and
PPP in L2TP sessions, however, you apply the service policy to a predefined configuration template
known as the virtual template interface. The virtual template interface is a logical entity that is applied
dynamically as needed to a connection. It is used to create and configure a virtual access interface (VAI).
The VAI uses the virtual template interface to create a session, which results in a VAI that is uniquely
configured for a specific user. All of the VAIs that use the virtual template interface inherit the service
policy applied to the template.
Note Not all of the QoS actions available through the modular QoS CLI are available to the virtual access
interface. For information about the available actions, see the
“Input and Output Policy Actions” section
on page 18-7.
For CBWFQ on the Cisco 10000 series router, when you apply a service policy to a virtual circuit (VC),
the VAIs that use that VC inherit the service policy of the VC. Any VAI that uses that VC is subject to
the queuing, policing, and marking actions defined in the VC service policy.
Note Do not apply service policies with CBWFQ actions to a VAI using a virtual template. The Cisco 10000
series router supports queuing only when you apply the service policy to a VC.
You can also configure per session rate limiting using a Cisco vendor specific attribute (VSA) in a
RADIUS user profile. For more information, see the
“Per Session Service Policy Using RADIUS”
section on page 18-5.
For RBE sessions, apply the service policy to the ATM VC or subinterface.

Cisco 10000 Series Specifications

General

Brand	Cisco
Model	10000 Series
Category	Network Router
Language	English