Supermicro SSE-F3548S/SSE-F3548SR Configuration User’s Guide
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Figure QoS-2: Relationship: ACL, Policy Map & Class Map
9.1.1.2
Policing
Policing involves creating a policer that specifies the bandwidth limits for the traffic. Each policer specifies
the action to take for packets thatare in or out of profile. Packets that exceedthe limits are out of profile
and various actions are carried out by the marker on out of profile packets, which may includedropping
the packet or markingdown the packet with a new user-defined value.
9.2
CoS-Based QoS
Supermicro switch features based on Class of Service (CoS) are:
•
Queuing
•
Scheduling
•
Bandwidth Management
•
Default Priority
9.2.1
Egress Queuing
The CoS priority of a packet is mapped to a traffic class.Supermicro switchesprovide support to configure
the mapping of CoS priority to a traffic class.Each traffic class is mapped to eight egress queues in the
switch.
The traffic class is taken from the CoS value of the ingress packet. If an ingress packet does not have a CoS
(untagged packets), the port default priority will be used.
Ingress Packets CoS-to-Traffic-class mappingEgress QueueEgress Packets
Figure QoS-3: Egress Queuing
The above figure shows the egress queuing procedure. When a tagged packet with CoS value 3(packet1)
arrives in the switch, the CoS to egress queuemapping for the particular destination port is lookedup.
Based on CoS to egress queue mapping, packets with CoS value 3 are queued in Queue-3 and transmitted.
Similarly, when a tagged packet with CoS value 7(packet2) arrives in switch, the CoS to egress queue
mapping for the particular destination port is lookedup. Based on CoS to egress queue mapping, packets
with CoS value 7 are queued in Queue-7 and transmitted
.
CoS Traffic Class
0
0
1
1
2
2
3
3
4
4
5
5
6
6
7
7
0
1
2
3 Pkt1
4
5
6
7 Pkt 2
Packet 1 with CoS 3
Packet 2 with CoS 7
Packet 1 with CoS 3
Packet 2 with CoS 7
