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EES4710BD 10 Slots L2/L3/L4 Chassis Switch
Fig 16-4 Classification process
Policing and remark: Each packet in classified ingress traffic is assigned an internal DSCP value
and can be policed and remarked.
Policing can be performed based on DSCP value to configure different policies that allocate
bandwidth to classified traffic. If the traffic exceeds the bandwidth set in the policy (out of profile),
the out of profile traffic can be allowed, discarded or remarked. Remarking uses a new DSCP value
of lower priority to replace the original higher level DSCP value in the packet; this is also called
“marking down”. The following flowchart describes the operations during policing and remarking.
Star
IP & non-IP
packets
Rea
d
s
i
ngress c
l
ass
ifi
cat
i
on
configuration info
Trust CoS value (IP & non-IP packets)
Trust IP pr
i
or
i
ty
(IP packets)
Generates
i
nter
i
or DSCP va
l
ue
consistent with the DSCP value
carried in packet header
QoS ACLs configured
at ingress?
CoS value carried with
packet?
Finish
Generate default internal
DSCP value (0)
Internal DSCP according
to default CoS value and
Cos-to-DSCP mapping
Internal DSCP according to
packet CoS value and
Cos-to-DSCP mapping
Trust DSCP value (IP packets)
(
opt
i
ona
l
)
De
fi
nes
DSCP-to-DSCP
mutation map
Finish Finish
Matching permit
entries?
Generates DSCP value
specified by ACLs
Inter
i
or DSCP va
l
ue
generated according to IP
Precedence value and
IP-Precedence-to-DSCP
mapping of the packet