NAT Technologies For IPv6Transition

With the rapid increase of users and rapid development of Internet services, IPv4addresses isapproaching exhausted. As the next-generation Internet core protocol, IPv6has a lot of advantagescompared to IPv4and will provide better and more efficient security services for network users.IPv4to IPv6transition is an imminent task. Meanwhile, with the development of the thirdgeneration mobile communication system, MIPv4to MIPv6transition has to be considered tosupport the handover of mobile terminals between different networks. Based on the analysis of theexisting IPv4/v6transition technologies, the thesis focuses on the study of network addresstranslation, NAT, based integrated transition technologies, especially on that of NAT66and IVI, astateless NAT technology. Some improved transition technologies and deployment schemes areproposed from the ISP’s point of view.Firstly, The thesis clarifies the necessity of IPv4/v6transition and compares the existing basictransitional technologies. Then it analyzes the combined Dual-Stack Lite and NAT444transitiontechnology and its unsolved issues. Secondly, considering the ISP’s network environment, animproved combined Dual-Stack Lite and IVI transition technology and its deployment schemes areproposed to effectively support the communication between local network and Internet withheterogeneous IP protocols. Thirdly, the thesis introduces an improved combinedIVI/NAT44/NAT66transition technology to tackle the limited IVI address space problem. Themodule design and logic flow of NAT66gateway are also provided. Furthermore the thesis studiesMIPv4and MIPv6transition technology and proposes an IVI-based Mobile IP transition technology.Deployment schemes and detailed analysis of IVI gateway are provided in accordance with refinedapplication scenarios together with related protocol procedure. Finally, with a comparison with theNAT-PT based transition technology, the thesis makes performance analysis of the proposedMIPv4/v6transition technology in terms of the communication delay.