Explicit Arbiter Rate Limits
Page 582
7950 XRS Quality of Service Guide
Profile Capped Policers
Profile capped mode has been introduced to enforce an overall in-profile burst limit to the CIR
bucket for ingress undefined, ingress explicit in-profile, egress soft-in-profile and egress explicit
in-profile packets. The default behavior when profile-capped mode is not enabled is to ignore the
CIR output state when an explicit in-profile packet is handled by an ingress or egress policer. The
explicit in-profile packets will consume CIR tokens up to 2xCBS at which point the bucket stops
incrementing and the CIR output for that type of packet enters the non-conforming state.
However, the non-conforming state is ignored by the forwarding plane and the packet continues to
be handled as in-profile. Thus, the total amount of in-profile traffic can be greater than the
configured CIR.
The profile-capped mode makes two changes:
•
At egress, soft-in-profile packets (packets received from ingress as in-profile) are treated
the same as explicit in-profile (unless explicitly reclassified as out-of-profile) and have an
initial policer state of in-profile
•
At both ingress and egress, any packet output from the policer with a non-conforming CIR
state are treated as out-of-profile (out-of-profile state is ignored for initial in-profile
packets when profile capped mode is not enabled)
The idea is that a profile capped policer trusts the in-profile state determined at ingress
classification or egress re-classification, the initial in-profile traffic is preferentially handled with
the CIR bucket (2xCBS instead of 1xCBS used by undefined or soft-out-of-profile traffic) and the
total amount of in-profile traffic output by the policer cannot exceed the CIR (including initial in-
profile traffic).
One other aspect to consider with profile-capped mode is the effect on stat-mode behavior. As will
be seen below, each stat-mode has a fixed number of counters in the NP and Q. The mapping of
packets to a counter is also fixed by the offered packet state (profile in, profile out, undefined, soft-
in-profile and soft-out-of-profile) in conjunction with the output state of the policer. Particularly of
note is the egress policer stat-modes and the behavior of soft-in-profile (from ingress) and profile
in (reclassified at egress) packets. In the non-capped mode, soft-in-profile is considered undefined
while in capped mode it is considered to be equivalent to profile in. Another aspect that causes
issues with ingress and egress stat-modes is the fact that initially green (profile in at ingress and
egress as well as soft-in-profile at egress), packets can actually turn yellow in the policer output.
demonstrates how the CIR rate and initial profile of each packet affects the output of
normal (non-profile-capped) and profile-capped mode policers.
Содержание 7950
Страница 12: ...Page 12 7950 XRS Quality of Service Guide List of Figures ...
Страница 16: ...Preface Page 16 7950 XRS Quality of Service Guide ...
Страница 82: ...Editing QoS Policies Page 82 7950 XRS Quality of Service Guide ...
Страница 90: ...Applying Network Queue Policies Page 90 7950 XRS Quality of Service Guide ...
Страница 96: ...Editing QoS Policies Page 96 7950 XRS Quality of Service Guide ...
Страница 98: ...Command Hierarchies Page 98 7950 XRS Quality of Service Guide ...
Страница 108: ...Command Hierarchies Page 108 7950 XRS Quality of Service Guide ...
Страница 156: ...Basic Configurations Page 156 7950 XRS Quality of Service Guide exit exit ...
Страница 164: ...Queue Depth Monitoring Page 164 7950 XRS Quality of Service Guide ...
Страница 304: ...Service Queue QoS Policy Commands Page 304 7950 XRS Quality of Service Guide ...
Страница 343: ...Ingress and Egress Queue Group Creation and Redirection 7950 XRS Quality of Service Guide Page 343 ...
Страница 368: ...Command Hierarchies Page 368 7950 XRS Quality of Service Guide ...
Страница 430: ...Configuration Commands Page 430 7950 XRS Quality of Service Guide ...
Страница 468: ...Basic Configurations Page 468 7950 XRS Quality of Service Guide exit exit no shutdown exit A SR config service ...
Страница 532: ...Editing QoS Policies Page 532 7950 XRS Quality of Service Guide ...
Страница 552: ...Editing Advanced Policies Page 552 7950 XRS Quality of Service Guide ...
Страница 598: ...Interaction Between Profile Preferred and Profile Capped Mode Page 598 7950 XRS Quality of Service Guide ...
Страница 600: ...Command Hierarchies Page 600 7950 XRS Quality of Service Guide ...
Страница 602: ...QoS Commands Page 602 7950 XRS Quality of Service Guide ...
Страница 610: ...Standards and Protocols Page 610 7950 XRS Quality of Service Guide ...
Страница 612: ... 2015 Alcatel Lucent All rights reserved 3HE 09868 AAAA TQZZA 01 ...