Video and voice traffic currently have the biggest share in the Internet. These applications require end-to-end Quality of Service (QoS) guarantees for each flow. The packet schedulers in the routers play an important role in providing end-to-end QoS support in the Internet. It is important that the implementation of packet schedulers scale with the steady increase in the data rates and the number of flows. In our previous work we proposed Window Based Fair Aggregator (WBFA) to decrease the number of flows. WBFA aggregates the flows preserving their end-to-end delay bounds with a relatively small aggregation delay. In this paper we present a detailed simulation study to demonstrate the features of WBFA and its effect on the performance of fair packet schedulers.