Aggregation of guaranteed service flows

It is common belief that the integrated services architecture (IntServ) is not scalable to large networks as, e.g., the global Internet. This is due to the ambitious goal of providing per-flow QoS and the resulting complexity of fine-grained traffic management. One solution to this problem is the aggregation of IntServ traffic flows in the core of the network. While one might suspect that aggregation leads to allocating more resources for the aggregated flow than for the sum of the separated flows if flow isolation is to be guaranteed, we show in this paper that for IntServ's guaranteed service flows this is not necessarily the case even if flow isolation is retained. We compare different approaches to describing the aggregated traffic and analyze their impact on bandwidth consumption and ease of flow management. Applications of these theoretical insights could be to use the derived formulas for resource allocation in either a hierarchical RSVP/IntServ, IntServ over DiffServ (differentiated services), or IntServ over ATM network.