Preserving quality of service guarantees in spite of flow aggregation

We investigate how quality of service may be guaranteed to a flow of packets in the presence of flow aggregation. For efficiency, multiple flows, known as the constituent flows, are merged together resulting in a single aggregate flow. After the network node where the aggregation occurs, packet schedulers are aware of the aggregate flow, but are unaware of its constituent flows. In spite of this, we show that quality of service may be guaranteed to the constituent flows, provided the aggregation is performed fairly. When the delay bound of a flow is de-coupled from the flow's reserved rate, flow aggregation preserves the delay bound. When the delay bound of a flow is coupled to the flow's reserved rate, flow aggregation preserves, and in some cases improves, the delay bound.