Reorganized and Compact DFA for Efficient Regular Expression Matching

—Regular expression matching has become a critical yet challenging technique in content-aware network processing, such as application identification and deep inspection. To meet the requirement of processing heavy network traffic at line rate, Deterministic Finite Automata (DFA) is widely used to accelerate regular expression matching at the expense of large memory usage. In this paper, we propose a DFA-based algorithm named RCDFA (Reorganized and Compact DFA), which dramatically reduces the memory usage while maintaining fast and deterministic lookup speed. Based on the dissection of real-life DFA tables, we observe that almost every state has multiple similar states, i.e. they share identical next-state transitions for most input characters. However, these similar states often distribute at nonadjacent positions in the original DFA table. RCDFA aims at reorganizing all similar states into adjacent entries, so that identical transitions become consecutive along the state dimension, ...

• Type: Journal
• Year: 2011
• Where: ICC
• Authors: Kai Wang, Yaxuan Qi, Yibo Xue, Jun Li
• Keywords: Communications, Deterministic Finite Automata, Deterministic Finite Automata Dfa, ICC 2011, Regular Expression Matching