Delay bounds for a network of guaranteed rate servers with FIFO aggregation

To support quality of service guarantees in a scalable manner, aggregate scheduling has attracted a lot of attention in the networking community. However, while there are a large number of results available for flow-based scheduling algorithms, few such results are available for aggregate-based scheduling. We study a network implementing guaranteed rate (GR) scheduling with first-in-first-out (FIFO) aggregation. We derive an upper bound on the worst case end-to-end delay for the network. We show that while for a specific network configuration, the derived delay bound is not restricted by the utilization level on the guaranteed rate, it is so for a general network configuration.