Preserving Out Of Profile State At Egress Policer - Alcatel-Lucent 7450 Quality Of Service Manual

Preserving Out of Profile State at Egress Policer

Traffic sent through an egress policer with a non zero CIR will be reprofiled by default based
on the CIR threshold of the egress policer. To accommodate designs where traffic is set to be
out of profile at ingress, and the out of profile state is required to be maintained by an egress
policer, the parameter profile-out-preserve can be configured under the egress policer.
Explicit egress reclassification to the profile takes precedence over the profile-out-preserve
operation.
Egress Policer CIR Packet Handling without Profile
Capped Mode
When an egress policer has been configured with a CIR (max or explicit rate other than '0')
and profile capped mode is not enabled, the policer's CIR bucket state will override the
ingress 'soft-in-profile' or 'soft-out-of-profile' state much like the ingress policer handles
initial profile 'undefined' packets. If the CIR has not been defined or been set to '0' on the
egress policer, the egress policer output state will be 'in-profile' for 'soft-in-profile' packets
and 'out-of-profile' for 'soft-out-of-profile' packets.
If a packet's profile has been reclassified at egress, the new profile classification is handled
similar to the ingress policer handling of initial 'in-profile' or 'out-of-profile' packets. When
a packet has been reclassified as 'hard-in-profile', it is applied to the egress policer's CIR
bucket using a 'threshold-bc' higher than the 'threshold-bc' derived from the policer's CBS
parameter, but the policer output profile state will remain 'in-profile' even if the higher
threshold is crossed. When a packet has been reclassified as 'hard-out-of-profile', it does not
consume the egress policer's CIR bucket depth and the policer output profile state remains
'out-of-profile'.
Egress Policer CIR Packet Handling with Profile Capped
Mode
When profile capped mode is enabled, the egress packet handling described in
CIR Packet Handling without Profile Capped Mode
First, the soft-in-profile received from ingress is handled in a similar fashion as egress explicit
profile in reclassification unless the packet has been reclassified to profile out at egress.
Second, explicit egress profile in and soft-in-profile that has not been reclassified to profile
out at egress are allowed to be marked out-of-profile by an egress policer with CIR not set to
0.
Quality of Service Guide
Class Fair Hierarchical Policing (CFHP)
is modified in three aspects.
Egress Policer
865