Future development and application trend of three-tier exchange

The three-tier exchange is a switching technique that began to appear around 1997, initially to address broadcast domain problems. After years of development, three-tier switching technology has become the main force to build a multiple-service fusion network. What changes are currently being faced in the application environment of the three-tier switch? What new technologies have been created? What is the development trend? What is the market demand for the future? Please see expert interpretation-

Production and development

The three-tier exchange (also known as multi-layer switching technology, or IP switching technology) is an exchange technique that began to appear before and after 1997, and is presented in relation to traditional exchange concepts. As we all know, the traditional exchange technology is in the OSI Network Reference Model of the second Layer-data link layer to operate, and the three-tier switching technology is in the network model of the third layer to achieve packet high-speed forwarding. The emergence of three-layer switching technology is mainly to solve the problem of broadcast domain in large scale networks, through Vsp?column=news&key=lan Target=_blank class=qqx_gjz> LAN divides a large switching network into several smaller broadcast domains, with three-tier exchange technology exchanged between the VLANs. The original three-layer switch is often the two-tier forwarding and three-tier exchange in two units, has not completed a complete three-layer switching function with a chip, such switches are often rack-like, such as 3Com Corebuider9000, Corebuider3500, Cisco 5505, 6509, Lucent's Cajun P550 and so on, generally has a specialized processing three layer data unit or the module.

In the traditional switch, the three-layer switching engine is often the bottleneck of the whole switch, and can not realize the three-layer exchange of the large-capacity wire-speed, and the bus structure is used between the module and the module. Following the advent of Gigabit Ethernet standards, several rack switches also use gigabit ports to achieve interoperability between modules and modules. 1998 Intel launched a 550T, 550S stackable three-layer switch, the backplane capacity of 2.1Gbps, can achieve 8 hundred Gigabit Port Line speed Exchange, this is the market at that time one of the earliest box switch, cost-effective is also relatively high. But whether it was a three-tier or rack-and-layer three-tier switch, the main function is only to isolate the broadcast domain, routing protocol support is relatively simple, only to support the RIP, OSPF and other small Network dynamic routing protocol, VLAN routing between the default is interoperability, there is no control function.

With the change of network scale, Ethernet technology moves from an office network to a local area network of an office building, and even to the whole campus net, and before 1998, the technology of campus network often uses the earliest FDDI technology and ATM technology. This application changes to the three-tier switch to put forward higher performance requirements, the control of data forwarding and wide-area network routing interconnection requirements are also higher, while reliability, usability requirements are greatly enhanced, two or three-layer switching function also developed by a separate chip to complete, Exchange capacity also developed from the initial 5Gbps to the current hundreds of Gbps level, resulting in some key technologies, such as crossbar technology, access control technology based on hardware wire speed, End-to-end QoS technology, richer protocol support, etc. See the details with the text.