Congestion management is required when the traffic to be sent out on an interface is greater than the link bandwidth. Congestion avoidance techniques are used when the traffic to be sent out on an interface is nearing the link bandwidth, so that proactive measures can be taken to prevent congestion. We will describe congestion management techniques in this section, and congestion avoidance techniques in the next section.
The congestion management techniques that help implement a DiffServ model for QoS are queuing and scheduling.
