Work-Conserving Fair-Aggregation Across Multiple Core Networks

In the effort of reducing or eliminating per-flow state at routers, hence making QoS schedulers scalable in the core Internet, flow aggregation outperforms dynamic packet state by providing better end-to-end delay guarantee. Work-conserving flow aggregation (WCFA) has the advantage of gaining work-conserving property at the cost of an extra per-hop delay. Most research on work-conserving flow aggregation so far has focused on a single level of flow aggregation within a single aggregation domain. In this paper, we investigate the per-hop behavior of flow aggregation over multiple aggregation domains. Moreover, in each aggregation domain, multiple aggregation levels are considered. We show that the aggregating cost happens only once in each aggregation domain over all aggregation levels, and higher level of flow aggregation provides lower per-hop delay guarantee.