Users Guide

To congure the weight factor for WRED and ECN capabilities, global buer pools for multiple queues, and associating a service class with
ECN marking, perform the following:
1 Congure the weight factor for the computation of average-queue size. This weight value applies to front-end ports.
QOS-POLICY-OUT mode
Dell(conf-qos-policy-out)#wred—profile weight number
2 Congure a WRED prole, and specify the threshold and maximum drop rate.
WRED mode
Dell(conf-wred) #wred—profile thresh-1
Dell(conf-wred) #threshold min 100 max 200 max-drop-rate 40
3 Congure another WRED prole, and specify the threshold and maximum drop rate.
WRED mode
Dell(conf-wred) #wred—profile thresh-2
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. The 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.
Quality of Service (QoS)
719