FIFO Systems and Aggregate Scheduling

Abstract

Aggregate scheduling arises naturally in many case. Let us just mention here the differentiated services framework (Section 2.4) and high speed switches with optical switching matrix and FIFO outputs.

The state of the art for aggregate multiplexing is surprisingly poor. We summarize this in the form of a conjecture in Section 6.3.1. In this chapter, we give a panorama of results, many of them are new. In Section 6.2, we give bounds for a service element in isolation that serves several flows in an aggregate. The particular service discipline is not known, but we assume that the aggregate receives a strict service curve guarantee. Then we are able to bound the service received by any subflow inside the aggregate. The bound corresponds actually to the worst case where a sub-flow receives the lowest priority.