PcapIndex: An index for network packet traces with legacy compatibility

Long-term historical analysis of captured network traffic is a topic of great interest in network monitoring and network security. A critical requirement is the support for fast discovery of packets that satisfy certain criteria within largescale packet repositories. This work presents the first indexing scheme for network packet traces based on compressed bitmap indexing principles. Our approach supports very fast insertion rates and results in compact index sizes. The proposed indexing methodology builds upon libpcap, the defacto reference library for accessing packet-trace repositories. Our solution is therefore backward compatible with any solution that uses the original library. We experience impressive speedups on packet-trace search operations: our experiments suggest that the index-enabled libpcap may reduce the packet retrieval time by more than 1100 times.