Time-shift scheduling is a new real-time rate-reservation protocol aimed at forwarding packages from multiple input flows to a single output channel. Each input flow, that is, each sequence of packets generated by a source and addressed to a single destination, is guaranteed a predetermined packet rate and an upper bound on packet delay. Time-shift scheduling is based on the novel technique of time shifting to prevent flow timestamps from increasing faster than the real-time clock. It satisfies the properties of rate-proportional delay, fairness, and efficiency. This is an improvement over existing protocols that fail to satisfy at least one of these properties.

The paper discusses the strengths and weaknesses of the related scheduling protocols of virtual clock, weighted fair queueing, and self-clocking fair queueing. The authors then present time-shift scheduling informally before presenting a formal definition. They then cover the bound on packet delay, the fairness of the protocol, and the end-to-end delay bounds for a path of time-shift schedulers. The paper ends with a discussion of related and future work.

The presentation is clear, includes definitions of the basic notions implied, and reports on a protocol that seems to be very effective for real-time applications. Readers should have a background in network protocols and architecture.