A Layer 2 IP sharing device based on the NPT mechanism

Abstract

In this article we introduce a design which named Network Port Translation (NPT) that can substitute the function of Network Address Translation (NAT) and can get better performance in translation. The different concept between NPT and NAT is that NPT worked in Layer 2 and NAT worked in Layer 3. Because the design of NPT is “Translation on Demand (ToD)” to the Service Port Number and do not execute any action in translation to the IP Address, the packet will forward directly and save a lot of processing time. NPT can improve the performance of translation significantly which include translation latency, packet throughput and reduce the loading of the device. At last, NPT also can support a high level network security environment which includes all internal and external networks by controlling the access action from client to client.