  Packet classification according to multi-field ruleset is a key component for
many network applications. Emerging software defined networking and cloud
computing need to update the rulesets frequently for flexible policy
configuration. Their success depends on the availability of the new generation
of classifiers that can support both fast ruleset updating and high-speed
packet classification. However, existing packet classification approaches focus
either on high-speed packet classification or fast rule update, but no known
scheme meets both requirements. In this paper, we propose Range-vector Hash
(RVH) to effectively accelerate the packet classification with a hash-based
algorithm while ensuring the fast rule update. RVH is built on our key
observation that the number of distinct combinations of each field prefix
lengths is not evenly distributed. To reduce the number of hash tables for fast
classification, we introduce a novel concept range-vector with each specified
the length range of each field prefix of the projected rules. RVH can overcome
the major obstacle that hinders hash-based packet classification by balancing
the number of hash tables and the probability of hash collision. Experimental
results demonstrate that RVH can achieve the classification speed up to 15.7
times and the update speed up to 2.3 times that of the state-of-the-art
algorithms on average, while only consuming 44% less memory.
