Aggregated Bit Vector Search Algorithms for Packet Filter Lookups

Florin Baboescu and George Varghese
June 3, 2001

Packet classification is important for applications such as firewalls, intrusion detection, and differentiated services. Existing algorithms for packet classification reported in the literature scale poorly in either time or space as filter databases grow in size. Hardware solutions such as TCAMs do not scale to large classifiers. However, even for large classifiers (say 100,000 rules), any packet is likely to match a few (say 10) rules. Our paper seeks to exploit this observation to produce a scalable packet classification scheme called Aggregated Bit Vector (ABV). Our paper takes the bit vector search algorithm (BV) described in \cite{lucent} (which takes linear time) and adds two new ideas, recursive aggregation of bit maps and filter rearrangement, to create ABV (which can take logarithmic time for many databases). We show that ABV outperforms BV by an order of magnitude using simulations on both industrial firewall databases and synthetically generated databases.

How to view this document

The authors of these documents have submitted their reports to this technical report series for the purpose of non-commercial dissemination of scientific work. The reports are copyrighted by the authors, and their existence in electronic format does not imply that the authors have relinquished any rights. You may copy a report for scholarly, non-commercial purposes, such as research or instruction, provided that you agree to respect the author's copyright. For information concerning the use of this document for other than research or instructional purposes, contact the authors. Other information concerning this technical report series can be obtained from the Computer Science and Engineering Department at the University of California at San Diego,

[ Search ]

This server operates at UCSD Computer Science and Engineering.
Send email to