Erlang B as a Performance Model for IP Flows

Flow-based networking has gained momentum in the research community in recent years. It allows improved performance guarantees and dynamic, load-aware routing. Flow-based networking takes the nature of traffic into account and considers the fact that multiple packets are a part of the same transaction. Blocking probability has been used as a performance parameter in circuit switched networks for a long time; however, it has not been used in IP networks, since traffic is not admission controlled. This paper investigates blocking as a generic performance parameter aiding performance modelling of flow-based networks. Simulation results are presented, underlining the observation that there is a relationship between traditional IP performance parameters and flow blocking. Furthermore, it outlines how blocking can be used in a practical context to assess performance and define thresholds for network actions.