Juniper JUNOS OS 10.3 - SOFTWARE Manual page 3318

Complete Software Guide for Junos
Configuring CoS on MPLS Provider Edge Switch Using IP Over MPLS (CLI Procedure)
3222
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OS for EX Series Ethernet Switches, Release 10.3
You can use class of service (CoS) within MPLS networks to prioritize certain types of
traffic during periods of congestion. This topic describes configuring CoS components
on a provider edge (PE) switch that is using IP Over MPLS.
This task describes now to create a custom DSCP classifier and a custom EXP rewrite
rule on the ingress PE switch. It includes configuring a policer firewall filter and applying
it to the customer-edge interface of the ingress PE switch. The policer firewall filter
ensures that the amount of traffic forwarded through the MPLS tunnel never exceeds
the requested bandwidth allocation.
For this procedure, we assume that the switch has already been configured for MPLS.
See "Configuring MPLS on Provider Edge Switches Using IP Over MPLS (CLI Procedure)"
on page 3401.
Import the default DSCP classifier classes to the custom DSCP classifier that you are
1.
creating:
[edit class-of-service]
user@switch#set classifiers dscp dscp1 import default
Add the expedited-forwarding class to this custom DSCP classifier, specifying a loss
2.
priority and code point:
[edit class-of-service]
user@switch#set classifiers dscp dscp1 forwarding-class expedited-forwarding
loss-priority low code-points 000111
Specify the values for the custom EXP rewrite rule,
3.
[edit class-of-service]
user@switch# set rewrite-rules exp e1 forwarding-class expedited-forwarding
loss-priority low code-point 111
Specify the number of bits per second permitted, on average, for the firewall policer,
4.
which will later be applied to the customer-edge-interface:
[edit firewall]
set policer mypolicer if-exceeding bandwidth-limit 500m
Specify the maximum size permitted for bursts of data that exceed the given
5.
bandwidth limit for this policer:
[edit firewall policer]
set mypolicer if-exceeding burst-size-limit 33553920
Discard traffic that exceeds the rate limits for this policer:
6.
[edit firewall policer]
set mypolicer then discard
To reference the policer, configure a filter term that includes the policer action:
7.
[edit firewall]
user@switch# set family inet filter myfilter term t1 then policer mypolicer
Apply the filter to the customer-edge interface:
8.
:
e1
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