Example: Aggregate Marking With Oversubscription Rate-Limiting Hierarchical Policy - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - POLICY MANAGEMENT CONFIGURATION GUIDE 2010-10-04 Configuration Manual

JunosE 11.3.x Policy Management Configuration Guide

Example: Aggregate Marking with Oversubscription Rate-Limiting Hierarchical Policy

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host1(config-rate-limit-profile)#conformed-action transmit final
host1(config-rate-limit-profile)#exceeded-action transmit conditional
host1(config-rate-limit-profile)#peak-rate 10000000
host1(config-rate-limit-profile)#exit
host1(config)#rate-limit-profile extrabw two-rate hierarchical
host1(config-rate-limit-profile)#committed-action transmit conditional
host1(config-rate-limit-profile)#conformed-action transmit conditional
host1(config-rate-limit-profile)#exceeded-action drop
host1(config-rate-limit-profile)#peak-rate 20000000
host1(config-rate-limit-profile)#exit
host1(config)#policy-list mypolicy
host1(config-policy-list)#classifier-group A parent-group extrabw
host1(config-policy-list-classifier-group)#rate-limit-profile indiv
host1(config-policy-list-classifier-group)#exit
host1(config-policy-list)#classifier-group B parent-group extrabw
host1(config-policy-list-classifier-group)#rate-limit-profile indiv
host1(config-policy-list-classifier-group)#exit
host1(config-policy-list)#classifier-group C parent-group extrabw
host1(config-policy-list-classifier-group)#rate-limit-profile indiv
host1(config-policy-list-classifier-group)#exit
host1(config-policy-list)#parent-group extrabw
host1(config-policy-list-parent-group)#rate-limit-profile extrabw
host1(config-policy-list-parent-group)#exit
Figure 5 on page 67 shows an aggregate rate limit that enables up to 2 Mbps of traffic
to be sent with a ToS value marked as 10. Traffic above that rate is sent with a ToS value
marked as 20 or 30 (depending on packet type) and traffic above 6 Mbps is dropped.
The 2 Mbps of traffic with the ToS value of 10 is oversubscribed among individual flows
A, B, and C, each of which can have up to 1 Mbps of traffic with the ToS value of 10. An
individual flow can mark a packet with the ToS value of 10, but if there is insufficient
bandwidth at the shared rate limit because of oversubscription, the packet is demoted
and remarked.
The demoted packets from flow A are marked with the ToS value of 20 but the demoted
packets from flows B and C are marked with the ToS value of 30. The shared rate limit
determines whether to demote the packet, in which case each individual rate limit selects
the new ToS marking. Individual flows are not required to mark demoted packets with
the same value.
The committed and conformed actions are transmit conditional so that all packets also
go through rate limit S, because rate limit S imposes the limit of 2 Mbps of traffic with a
ToS value of 10 (total across A, B, and C).
Committed packets are transmitted conditionally to rate limit S, which has a peak rate
of 6 Mbps and a committed rate of 2 Mbps; these packets can be demoted by S to Y
(yellow), in which case they are remarked with the ToS value of 20 or 30. If S leaves them
as G (green), they are marked with the ToS value of 10. All conformed packets from A,
B, and C are also transmitted conditionally to S but arrive as Y because rate limits do not
promote packets in color. S is color-aware so these Y packets do not take away G tokens,
leaving them reserved only for the G packets coming from A, B, and C.
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