Cisco Systems ASR 1000 manual Two-Rate Three-Color Policing and Marking

Chapter 5 Quality of Service and Bandwidth Management

Two-Rate Three-Color Policing and Marking

Two-Rate Three-Color Policing and Marking

Traffic policing is a traffic regulation mechanism that is used to limit the rate of traffic streams. Policing allows you to control the maximum rate of traffic sent or received on an interface. When the traffic rate exceeds the configured maximum rate, policing drops or re-marks the excess traffic.

The ETSI TS 102 333 Traffic Management (Tman) package defined a number of properties to allow traffic policing to be explicitly enabled. However, because the current H.248 standard only supported specifying one rate with a traffic flow, the only action available in the H.248 standard for non-conforming packets had been to discard them. (See the “Enhanced Event Notification and Auditing” section on page 11-2).

The Two-Rate Three-Color Policing and Marking feature is an enhancement to how the DBE polices traffic flow by introducing two-rate policing and three-color marking.

The DBE previously supported three tman properties—pol (policing), sdr (sustainable data rate), and mbs (maximum burst size). In supporting the Two-Rate Three-Color Policing and Marking feature, the DBE uses one additional property of the ETSI TS 102 333 Traffic Management (Tman) package:

pdr (peak data rate)—Defines the peak data rate in bytes per second that is permitted for the stream.

See the “H.248 Traffic Management Package Support” section on page 5-1for more information on the tman properties.

Enabling Two-Rate Three-Color Policing and Marking

All of the following conditions must occur to enable the Two-Rate Three-Color Policing and Marking feature for a specific flow:

•The DSCP value is provisioned via diffserv package during call setup.

•The sdr and mbs are provisioned via the Tman package during call setup. (The mbs property is used for pdr policing as well and has an assumed minimal value of 1500 bytes.)

•Two DSCP values (control and marker DSCPs) and the pdr coefficient are configured via the control-dscpmarker-dscppdr-coefficientCLI.

•The control-dscpvalue configured must match the diffserv DSCP value for a specific flow to enable the Two-Rate Three-Color Policing and Marking feature.

If any one of the conditions is not met, this feature is not enabled for the flow.

Implementing Two-Rate Three-Color Policing and Marking

In the Two-Rate Three-Color Policing and Marking feature, only two rates—sdr and pdr—allow traffic to be policed into three categories of traffic, which are handled as follows:

•Traffic conforming to both sdr and pdr.

These packets are colored using the DSCP value provisioned via the H.248 diffserv package; that is, H.248 passes the DSCP value. These packets are forwarded and the DSCP value comes from the H.248 diffserv package.

Cisco IOS XE Integrated Session Border Controller Configuration Guide for the Cisco ASR 1000 Series Aggregation Services Routers

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