Basic Two-Rate Three-Color Policers; Two-Rate Three-Color Policer Overview - Juniper EX9200 Features Manual

CHAPTER 15

Basic Two-Rate Three-Color Policers

Two-Rate Three-Color Policer Overview

Copyright © 2016, Juniper Networks, Inc.
Two-Rate Three-Color Policer Overview on page 161
Example: Configuring a Two-Rate Three-Color Policer on page 162
A two-rate three-color policer defines two bandwidth limits (one for guaranteed traffic
and one for peak traffic) and two burst sizes (one for each of the bandwidth limits). A
two-rate three-color policer is most useful when a service is structured according to
arrival rates and not necessarily packet length.
Two-rate three-color policing meters a traffic stream based on the following configured
traffic criteria:
Committed information rate (CIR)—Bandwidth limit for guaranteed traffic.
Committed burst size (CBS)—Maximum packet size permitted for bursts of data that
exceed the CIR.
Peak information rate (PIR)—Bandwidth limit for peak traffic.
Peak burst size (PBS)—Maximum packet size permitted for bursts of data that exceed
the PIR.
Two-rate tricolor marking (two-rate TCM) classifies traffic as belonging to one of three
color categories and performs congestion-control actions on the packets based on the
color marking:
Green—Traffic that conforms to the bandwidth limit and burst size for guaranteed
traffic (CIR and CBS). For a green traffic flow, two-rate TCM marks the packets with
an implicit loss priority of
Yellow—Traffic that exceeds the bandwidth limit or burst size for guaranteed traffic
(CIR or CBS) but not the bandwidth limit and burst size for peak traffic (PIR and PBS).
For a yellow traffic flow, two-rate TCM marks packets with an implicit loss priority of
and transmits the packets.
medium-high
Red—Traffic that exceeds the bandwidth limit and burst size for peak traffic (PIR and
PBS). For a red traffic flow, two-rate TCM marks packets with an implicit loss priority
of and, optionally, discards the packets.
high
low and transmits the packets.
161