Balance based performance enhancement for interactive TCP traffic replay

Interactive network traffic replay plays an important role in testing and evaluating in-line network security devices such as Firewalls, IPSs, etc. In this paper we present a balance-based method for improving the performance of interactive TCP traffic replay. The new method is based on the inherent feature of the TCP protocol, that is, two communicating peers keep synchronized with each other using data acknowledgment. This feature is converted as a balance mechanism in interactive TCP traffic replay and incorporated into the current state-based method. In this way, the cost of state-checking can be significantly reduced and the replay performance is thus enhanced. To validate the effectiveness of the method we implement it by building an interactive replay system. The experimental results indicate that: 1) balance-checking reduces the overhead of state-checking by 40%; 2) the balance-based method enhances the overall replay performance by an average of 5% when the actual TCP traffic traces are replayed.