Exploiting Non-Uniformities in Redundant Traffic Elimination

Abstract

Protocol-independent redundant traffic elimination (RTE) at the network layer is a method of detecting and removing redundant chunks of data from data packets using caching at both ends of a network link or path. In this paper, we propose a set of techniques to improve the effectiveness of packet-level RTE. In particular, we consider two bypass techniques, with one based on packet size, and the other based on content type. Both bypass techniques are effective in reducing the processing requirements of RTE, with little or no adverse impact on redundancy detection. The bypass techniques apply at the front-end of the RTE pipeline. Within the RTE pipeline, we propose chunk overlap and oversampling as techniques that can improve redundancy detection, while obviating the storage and processing requirements associated with chunk expansion at the network endpoints as suggested by previous research. Finally, we propose savings-based cache management at the backend of the RTE pipeline, as an improvement to the commonly used FIFO-based cache management. We evaluate our techniques on full-payload packet-level traces from a university environment. Our results show that the 11-12% savings achieved with typical RTE can be improved to 16-18% with our techniques.