  Quick network address translation (NAT) is proposed to improve the network
performance of the NAT system on the commodity server by three ways. First, the
quick NAT search algorithm is designed to use the Hash search instead of the
sequential search to reduce latency when looking up the NAT rule table. Second,
to leverage the power of the multi-core central processing unit (CPU) and the
multi-queue network interface card, Quick NAT enables multiple CPU cores to
process in parallel. The localized connection tracking table and the
compare-and-swap based lock-free NAT Hash tables are designed to eliminate the
lock overhead. Third, Quick NAT uses the polling and zero-copy delivery to
reduce the cost of interrupt and packet copies. The evaluation results show
that Quick NAT obtains high scalability and line-rate throughput on the
commodity server.
