Accton Technology ES4710BD User Manual page 335

Star
Reads ingress classification
configuration info
IP & non-IP
packets
Interior DSCP value
generated according to IP
Precedence value and
IP-Precedence-to-DSCP
mapping of the packet
QoS ACLs configured
at ingress?
Matching permit
entries?
Generates DSCP value
specified by ACLs
Finish
Policing and remark: Each packet in classified ingress traffic is assigned an internal DSCP value
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.
EES4710BD 10 Slots L2/L3/L4 Chassis Switch
Trust CoS value (IP & non-IP packets)
Trust DSCP value (IP packets)
Trust IP priority
(IP packets)
Generates interior DSCP value
consistent with the DSCP value
Finish
Generate default internal
DSCP value (0)
Fig 16-4 Classification process
and can be policed and remarked.
carried in packet header
(optional) Defines
DSCP-to-DSCP
mutation map
CoS value carried with
Internal DSCP according to
packet CoS value and
Cos-to-DSCP mapping
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packet?
Internal DSCP according
to default CoS value and
Cos-to-DSCP mapping
Finish