Research on IPv4/v6 integrated networking in NGN (1)

In the service bearer layer of the Next Generation Network (NGN), IPv6 can expand the IP address space, increase the security of the IP network, and improve the network service quality. In the long run, it has a good technical foresight and broad application space. However, replacing the existing IPv4 network with an IPv6 network is a very complicated and difficult problem. This not only affects the network layer, but also changes in the network layer protocol, changes occur from the link layer to the application layer.

Ii. in-depth understanding of network transition issues

People Constantly understand the transition from an IPv4 network to an IPv6 network. The earliest term used in the ietf rfc and DRAFT for network transition was "migration". At this time, I realized that I had abandoned the existing widely used IPv4 network, to build a pure IPv6 network. This will not only involve investment protection, device compatibility, technical compatibility, and application compatibility issues, but also lead to a gap between technology and application. Despite this, IETF's major technical staff are optimistic about the transition from an IPv4 network to an IPv4 network. They believe that IPv4 networks can be migrated to IPv6.

With the deepening of research, more and more problems may be encountered during the network transition process, and the problem analysis becomes more and more complex. IETF also recognizes that there will be no large-scale, extensive, and overall network migration; the transition process will be long-term and continuous. In this case, the term used by IETF for network transition is changed to "transition )". In order to conduct a more in-depth and comprehensive analysis of the problem, IETF established a "next-generation network transition Workgroup (Ngtrans)". The results of this workgroup are reflected in 14 RFC and more than 20 DRAFT. Some network transition ideas are proposed, and the network transition toolbox is formed.

Currently, IETF uses the term "interoperation" for network transition, and the corresponding "Next Generation Network transition Workgroup (Ngtrans)" has also stopped working, instead, it is the newly established "IPv6ops )". The transformation of IETF's understanding is based on a more in-depth study of the IPv4 to IPv6 transition process. IETF believes that "transition is long-term and integration is inevitable". Therefore, the current primary consideration is not how to replace IPv4 networks with IPv6 networks, instead, we should focus on how to achieve the integration of IPv4 and IPv6. Only when the IPv4 network can be well integrated with the IPv6 network can the network be smoothly transitioned. Therefore, it is imperative to study the interoperability between IPv4 and IPv6 networks.

The above cognitive changes of IETF on IPv6 are fully reflected in the research topic of the IPv6ops Working Group. In IPv6ops, the focus of research is not on the specific methods and methods in the network transition toolbox, but on the IPv4/v6 integrated networking solution for different network application environments. Currently, the typical network application environments of IPv6ops research include Backbone Networks, enterprise networks, ISP network, and UNMANAGEDNETWORKs) and 3GPP networks (including hosts and terminals. However, these studies are in the DRAFT phase (DRAFT), and many of the contents of the DRAFT are currently blank (only directories are listed), and there is still much research to be done. On the one hand, because the requirements of typical network environments are not easy to unify, different network operation entities (Network supplier NP, service supplier SP, content supplier CP, etc.) have different requirements for the network, therefore, we can foresee that the debate on a typical network environment is intense and long-term. On the other hand, the network itself is also under development and change, and network security, authentication and billing, control and management, performance monitoring and other issues are under research, these evolving contents will also affect the research on IPv4/v6 integrated networking technology for different network application environments. Another important factor is that IP technology is increasingly widely used in telecom networks, which puts forward higher requirements for IPv4/v6 integrated networking. All these factors make the research on IPv4/v6 integrated networking technology long term, involving multiple aspects, restricted by multiple factors.

In the long run, IPv4 and IPv6 technologies will coexist in the network for a long time (Co-existence ). Different network operators can choose the IP layer protocol and the integrated networking mode based on their actual conditions. In the future, an IP network will be an IPv4 network and an IPv6 network integration network.

In general, as the research on IPv4 to IPv6 transition technology continues to deepen, the understanding of the transition issue also deepens, and IETF's understanding of this issue has also gone through the migration (migration) (transition) integration (interoperation) (Co-existence) phase.