Assured Forwarding

Assured Forwarding (AF) is a mechanism for assurance of delivery, given a defined rate.

In case of congestion, traffic that exceeds the rate have a higher probability of being dropped.

The four AF classes have the same priority. For each class, packets are given a drop probability.

Drop probability Class 1 Class 2 Class 3 Class 4
Low AF11 AF21 AF31 AF41
Medium AF12 AF22 AF32 AF42
High AF13 AF23 AF33 AF43