Juniper EX9200 Series, Features Manual

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along with their associated burst sizes, the CBS and peak burst size (PBS). Traffic is
marked as belonging to one of three categories (green, yellow, or red) based on whether
the packets arriving are below the CIR (green), exceed the CIR (yellow) but not the
PIR, or exceed the PIR (red).
A two-rate three-color policer is most useful when a service is structured according to
arrival rates and not necessarily packet length.
Policer actions are implicit or explicit and vary by policer type. The term Implicit means
that Junos assigns the loss-priority automatically. Table 3 on page 6 describes the
policer actions.
Table 3: Policer Actions
Configurable Action Implicit Action Marking Policer
None Assign low loss
priority Green (Conforming) Single-rate two-color
Assign low or high loss
priority, assign a
forwarding class, or
discard
On some platforms,
you can assign
medium-low or
medium-high loss
priority None Red (Nonconforming)
None Assign low loss
priority Green (Conforming) Single-rate
three-color
None Assign medium-high
loss priority Yellow (Above the CIR
and CBS)
Discard Assign high loss
priority Red (Above the EBS)
None Assign low loss
priority Green (Conforming) Two-rate three-color
None Assign medium-high
loss priority Yellow (Above the CIR
and CBS)
Discard Assign high loss
priority Red (Above the PIR
and PBS)
Forwarding Classes and PLP Levels
A packet’s forwarding class assignment and PLP level are used by the Junos OS
class of service (CoS) features. The Junos OS CoS features include a set of mechanisms
that you can use to provide differentiated services when best-effort traffic delivery is
insufficient. For router (and switch) interfaces that carry IPv4, IPv6, and MPLS traffic,
you can configure CoS features to take in a single flow of traffic entering at the edge of
Copyright © 2016, Juniper Networks, Inc. 6
Traffic Policers Feature Guide for EX9200 Switches