Connectivity Guide

• Explicit congestion notication (ECN)—This is an extension of WRED. Instead of dropping the packets when the average queue
length crosses the minimum threshold values, ECN marks the Congestion Experienced (CE) bit of the ECN eld in a packet as ECN-
capable trac (ECT).
1 Congure a WRED prole in CONFIGURATION mode.
OS10(config)# wred wred_prof_1
2 Congure WRED threshold parameters for dierent colors in WRED CONFIGURATION mode.
OS10(config-wred)# random-detect color yellow minimum-threshold 100 maximum-threshold 300
drop-probability 40
3 Congure the exponential weight value for the WRED prole in WRED CONFIGURATION mode.
OS10(config-wred)# random-detect weight 4
4 Enable ECN.
OS10(config-wred)# random-detect ecn
5 Enable WRED/ECN on a queue.
OS10(config)# class-map type queuing c1
OS10(config-cmap-queuing)# match queue 2
OS10(config-cmap-queuing)# exit
OS10(config)# policy-map type queuing p1
OS10(config-pmap-queuing)# class c1
OS10(config-pmap-c-que)# random-detect wred_prof_1
6 Enable WRED/ECN on a port.
OS10(config)# interface ethernet 1/1/1
OS10(conf-if-eth1/1/1)# random-detect wred_prof_1
7 Enable WRED/ECN on a service-pool.
OS10(config)# system qos
OS10(config-sys-qos)# random-detect pool 0 wred_prof_1
NOTE
: On the S4200–ON Series platform, enable ECN globally only. Also, apply ECN congurations only at the queue level. You
cannot congure ECN at the interface or service-pool levels. If you try to apply the ECN conguration at the interface or
service-pool levels, the conguration is not accepted.
1 Congure a WRED prole in CONFIGURATION mode.
OS10(config)# wred wred_prof_1
2 Congure WRED threshold parameters for dierent colors in WRED CONFIGURATION mode.
OS10(config-wred)# random-detect color yellow minimum-threshold 100 maximum-threshold 300
drop-probability 40
3 Congure the exponential weight value for the WRED prole in WRED CONFIGURATION mode.
OS10(config-wred)# random-detect weight 4
4 Congure the ECN threshold parameters in WRED CONFIGURATION mode.
OS10(config-wred)#random-detect ecn minimum-threshold 100 maximum-threshold 300 drop-
probability 40
5 Exit WRED CONFIGURATION mode.
OS10(config-wred)#exit
6 Enter QOS POLICY-MAP mode and create a queuing policy type.
OS10(config)#policy-map type queuing pol-map-1
7 Create a QoS class for the queuing policy type.
OS10(config-pmap-queuing)#class default
8 Assign a WRED prole to the specied queue.
OS10(config-pmap-c-que)#random-detect prof1
9 Exit CLASS MAP and POLICY MAP modes.
OS10(config-pmap-c-que)#exit
OS10(config-pmap-queuing)#exit
10 Enter SYSTEM QOS mode.
OS10(config)#configure system-qos
Quality of service
793