QOS Class Based Weighted Fair Queuing and ECN

QOS Class Based Weighted Fair Queuing and ECN

 

ECN: It makes WRED a little proactive as it does not drops the packets randomly but try to tell the sender to slow down. Router mark the packets with ECN bits at the end of dscp bits.

00-router is no ECN capable
01-endpoints are ECN capable
10-endpoints are ECN capable
11-Congestion experienced, router sends back ECN echo back to ECN compatible host and ask it to slow down.
 

R3 Config
class-map match-all HTTP
 match  dscp af41
!
!
policy-map HTTP-AF41
 class HTTP
  bandwidth 128
  random-detect dscp-based
  random-detect ecn

interface Serial1/0
 service-policy output HTTP-AF41