Features and evolution of next-generation networks and IPv6 protocols

NGN, or "Next Generation Network", is a general concept. Up to now, the next generation network has no definite definition. However, the features and main technologies of the Next Generation Network have gradually become apparent.

The features of the Next Generation Network mainly include: a) the network structure and function organization of the Next Generation Network should be an open distributed structure; B) the architecture of the Next Generation Network is actually IP technology + optical network, optical Networks will evolve into all-optical networks.

As the next generation network is constantly developing, its corresponding technologies are gradually formed in the development process. Currently, the main technologies applied to the next generation network are: IPv6, Softswitch technology, optical switching and smart optical network, optical fiber high-speed transmission technology, broadband access, man, IP terminal and network security technology.

IPv6 evolution and compatibility with IPv4
IP is a key protocol in the Internet. The birth of IPv6 is undoubtedly a huge progress, but we must not ignore the role of IPv4 in the past and future networks. As a large number of currently used devices support IPv4, communication operators must fully consider how to evolve to IPv6. IPv6 will be implemented at the network application layer and transport layer. devices that adopt IPv6 in advance also need IPv4 support on the backbone network. In this way, the interconnection and compatibility between IPv6 and IPv4 protocols need to be fully considered and solved. IPv6 has fully considered this transition issue during design, and supports three main technologies: Dual Stack, tunnel, and conversion.

Dual-stack Technology: New IPv6 devices can be backward compatible with IPv4, while IPv4 devices can be programmed using IPv4 and IPv6 protocol stacks to process their respective packages as appropriate. A dual-stack host can send and receive IPv4 and IPv6 data. A dual-Stack Router can forward any package.

Tunneling Technology: Transfer packets between two IPv6 domains through an IPv4 network. Therefore, dual-stack nodes use IPv4 headers to encapsulate IPv6 packets. Then, the package uses the IPv4 network tunnel to select the route until it reaches the second IPv6 domain. After the IPv4 header is removed from the second node, the packet is processed accordingly.

Conversion Technology: To solve the interoperability problem between IPv6 and IPv4 versions, a converter must be used. An IPv6 computer generates a destination address containing IPv4, but uses an IPv6-encoded datagram. The IPv6 computer sends the datagram to the converter. The Converter uses IPv4 to communicate with the destination site. when it receives a response from the destination site, it converts the IPv4 datagram to an IPv6 datagram and sends it back to the IPv6 source site.

IPv6 features
Compared with IPv4, IPv6 has two attractive features: IPv6 adopts the 128-bit address format while IPv4 adopts the 32-bit address format. Therefore, IPv6 increases the address space by 296; the other is that IPv6 is more capable of supporting mobile data services and will become one of the important protocols for the third-generation mobile communication in the future. At the same time, IPv6 overcomes and solves some IPv4 defects and problems. For example, IPv4 does not take into account the rapid development of Internet services, which imposes certain restrictions on the maintenance of Route tables and the provision of Fast Routing. IPv6 solves this defect. IPv6 simplifies the IP Header Format, provides data flow labels, and provides a simple method for transmitting headers, which can greatly shorten the processing time of packet headers in routers. IPv6 supports automatic Address Configuration, security protection, authentication, and encryption. without human intervention, the host can directly connect to all the information required by the Internet.

IPv6 maintains many successful features of IPv4. IPv6 still supports connectionless transmission; allows the sender to select the size of the datagram; requires the sender to specify the maximum number of hops before the datagram arrives at the destination site, and retains the segment and original route selection in IPv4. In addition, IPv6 has added the following five new features:

* Larger address space.

* Flexible Header Format.

* Network resources can be pre-allocated.

* The Protocol is simplified.

* Supports Protocol extensions.

In IPv6, a large range of addresses must also make it easy for Internet administrators to read and manipulate these addresses. The "dot-decimal notation" dotted decimal notation used by IPv4 is not convenient. Therefore, the IPv6 designers recommend that you use the "colon hexadecimal notation" hexadecimal notation ), each 16-bit value is expressed in hexadecimal notation and separated by a colon.

IPv6 has three basic address types: unicast address, cluster address, and multicast address. Unicast is a traditional point-to-point communication, and the datagram selects a shortest path to reach the destination site. A cluster is a set of computers that share a network address. A data packet is sent to the nearest member of the group after a shortest path is selected. Multicast is a one-to-multiple-point communication, that is, the destination site is a group of computers, which can be transmitted to each member of the group through hardware multicast or broadcast in different places.

Conclusion
With the development of the Internet, there will be more and more people accessing the internet, and the lack of IP Address resources will become a bottleneck restricting its development. In addition, with the rapid development of mobile communication, operators urgently need to seek new ways to reduce network costs and develop new businesses. Only in this way can they ensure their sustainable development and take the initiative in the competition. The emergence and development of next-generation networks have just provided such an important opportunity and have become an unstoppable development trend. IPv6 represents the Internet Protocol of the next generation and is the core technology of the Next Generation Network. Its development prospects are huge. Although IPv4 and IPv6 will coexist for a long period of time, it is bound to transition to IPv6.

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