On the use of Accounting Data for QoS-aware IP Network Planning Alan Davy, Dmitri Botvich, Brendan Jennings Telecommunications Software & Systems Group, Waterford Institute of Technology, Cork Road, Waterford, Ireland {adavy, dbotvich, bjennings}@tssg.org Abstract. We present an economically efficient framework for provision of essential input for QoS-aware IP network planning. Firstly, we define a process for reuse of network accounting data for construction of a QoS-aware network demand matrix. Secondly, we define a process for estimation of QoS-related effective bandwidth coefficients from packet traces collected per traffic classe. Taken together, these processes provide the necessary input required to plan a network in accordance with QoS constraints. We present results of a sensitivity analysis of the demand estimation process, and of an economic analysis of the relative merit of deployment of our approach in comparison to a traditional direct measurement-based approach. We conclude that although there is a degree of inaccuracy in our network demand estimation process this inaccuracy is within acceptable bounds, and that this is offset by the potential for significant cost reductions for the ISP. Keywords: Network Planning, Accounting, Effective Bandwidth, QoS 1 Introduction Network planning typically involves the use of dedicated network monitoring hardware to gather and collate large amounts of network traffic data, which is then analysed to identify an optimal network configuration design reflecting estimated demand and specified Quality of Service (QoS) requirements. Use of dedicated hardware means that this approach is relatively expensive, incurring costs in hardware procurement and maintenance, in addition to significant training/operational costs. In previous work [1] we presented an initial QoS-aware network planning approach based on using pre-existing network accounting data as an alternative source of input. In this paper we augment that work by providing a detailed sensitivity evaluation of our approach. We propose and evaluate a light-weight process for estimation of QoS aware effective bandwidth coefficients, which can be used to construct a QoS-aware demand matrix, providing the necessary input for QoS-aware network planning. In addition, we offer an economic analysis comparing the cost of deploying a traditional direct measurement based system to our approach. The paper is organised as follows: §2 discusses related work in the areas of demand matrix and effective bandwidth estimation. §3 describes our proposed network planning architecture. §4 presents our process for estimation of QoS aware