Earliest Due Date (EDD)

• Unlike WFQ, delay bound is independent of bandwidth requirement

• Packet with earliest deadline selected

• EDD prescribes how to assign deadlines to packets

• Deadline = expected arrival time + delay bound

• “Expected” arrival time is the time the packet should arrive according to traffic specification (to deal with bunching of packets downstream)

• Delay bound is the smallest feasible bound, computed assuming worst-case arrival pattern from all flows

Xmin1 = 10

Xmin2 = 4

3

3

2

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