An Enhanced NAT-PT Model
一个加强的NAT-PT模型

NAT-PT(network address translation + protocol translation) would allow IPv4 nodes to communicate with IPv6 nodes transparently by translating the IPv6 address into a registered V4 address. However, NAT-PT would fall flat when the pool of V4 addresses is exhausted. NAPT-PT multiplexes the registered address' ports and will allow for a maximum of 63K outbound TCP and 63K UDP sessions per IPv4 address, but it is unidirectional. In this paper, a novel solution ENAT-PT (enhanced NAT-PT) is presented which allows for a great number of inbound sessions by using a single V4 address. The main idea of ENAT-PT is the use of session parameters instead of source address for session identification. By using ENAT-PT, it is easy to visit V6 networks from a V4 network with a small address pool.