Users Guide

Dell(conf-wred) #threshold min 300 max 400 max-drop-rate 80
4. Create a global buer pool that is a shared buer pool accessed by multiple queues when the minimum guaranteed buers for
the queue are consumed. S4820T platform supports four global service-pools in the egress direction.
mode
Dell(conf) #service-pool wred green pool0 thresh-1 pool1 thresh-2
Dell(conf) #service-pool wred yellow pool0 thresh-3 pool1 thresh-4
Dell(conf) #service-pool wred weight pool0 11 pool1 4
5. Create a service class and associate the threshold weight of the shared buer with each of the queues per port in the egress
direction.
INTERFACE mode
Dell(conf-if-te-0/8)#Service-class buffer shared-threshold-weight
Guidelines for Conguring ECN for Classifying and Color-Marking
Packets
Keep the following points in mind while conguring the marking and mapping of incoming packets using ECN elds in IPv4 headers:
• Currently Dell Networking OS supports matching only the following TCP ags:
– ACK
– FIN
– SYN
– PSH
– RST
– URG
In the existing software, ECE/CWR TCP ag qualiers are not supported.
• Because this functionality forcibly marks all the packets matching the specic match criteria as ‘yellow’, Dell Networking OS does
not support Policer based coloring and this feature concurrently.
• If single rate two color policer is congured along with this feature, then by default all packets less than PIR would be considered
as “Green” But ‘Green’ packets matching the specic match criteria for which ‘color-marking’ is congured will be over-written
and marked as “Yellow”.
• If two rate three color policer is congured along with this feature then,
– x < CIR – will be marked as “Green”
– CIR < x< PIR – will be marked as “Yellow”
– PIR < x – will be marked as “Red”
But ‘Green’ packets matching the specic match criteria for which ‘color-marking’ is congured will be over-written and marked as
“Yellow”.
Sample conguration to mark non-ecn packets as “yellow” with Multiple trac class
Consider the example where there are no dierent trac classes that is all the packets are egressing on the default ‘queue0’.
Dell Networking OS can be congured as below to mark the non-ecn packets as yellow packets.
!
ip access-list standard ecn_0
seq 5 permit any ecn 0
Quality of Service (QoS)
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