Implementation Mechanism and Performance Analysis of a Novel NAT System

NAT is one of the effective solutions developed by IETE to the network address exhaustion of IPv4.Owing to the bottle-neck of performance resulting from complicated implementation and overcharge of NAPT based on GP-CPU or ASIC in the past,an implementation scheme was put forward in the paper,which is called NAT/NAPT based on Programmable Network Processors IXP2400.Meanwhile,the NAT system which has firewall function and contains a pair of Intel IXP2400 was designed and implement-ed by the author.And the performance analysis of the NAT system was made,which operates in switch-over mode(NAT or NAPT) based on the fullness of the available global addresses or user configuration,can support more than six hundreds of thousands of concurrent TCP/UDP sessions and sustain the full line rate on two Gigabit Ethernet links,and it is found that the NAT subsystem can successfully achieve the multiplexing of network address,effectively improve the performance of NAT/NAPT processing and over-come the bottleneck of performance in traditional implementation of NAT.