Infiltration of Ethernet switching technology into metropolitan area Network

With the development of network technology and the popularization of information application, Ethernet switch has been used more and more widely. More importantly, it began to penetrate from the simple LAN application to the metropolitan area Network, thus attracting more operators ' eyes.

The rapid growth of the switch market, in addition to the overall growth of the network market, mainly benefited from the following aspects. First of all, Ethernet switching technology is becoming mature, and the cost is dropping rapidly. With the increasing maturity of Ethernet switching technology, the cost of switching chips is also greatly reduced. At the same time, the integration of the chip has become more and more high, many of the previous functions need to be implemented through the peripheral components or software are integrated in the main chip, so that the structure of the switch is continuously simplified, thereby further reducing the cost. The lower cost of the 10/100m switch allows the dual-speed hub to exit the market. Now, in addition to the very individual small network and the broadband community is still using the 10M hub, the 10/100m switch has become an indispensable basic equipment in the network. The second is the wide application of optical fiber Ethernet technology. Compared to ATM, Gillette has a significant cost advantage over Ethernet. Ten-Gigabit Ethernet 802.1AE Standard is directly aimed at the backbone of the metropolitan area Network, the provision of LAN and WAN two standards, so that ten-gigabit Ethernet in the future backbone of the metropolitan area network with the development of POS technology with a positive competitive strength. It is based on the above factors, fiber-optic Ethernet technology in the backbone of the metropolitan area Network convergence and access are more and more widely used. With the help of telecom operators, fiber-optic Ethernet technology has been more fully used, because these industries for ATM, POS, such as QoS, fast self-healing, such as carrier-level features not too harsh requirements, but very sensitive to price. In addition, the growth of the traditional LAN market is not only within the system of the metropolitan Area Network, Enterprise informatization, education information and e-government construction require a large number of switches to form a local area network, which gives the switch market a stable foundation of support.

At present, the technology development of Ethernet switch also presents a new trend. With the rapid decline in the cost of Gigabit Ethernet, the Gillette switch is no longer an unattainable luxury, and most businesses, including small and medium-sized enterprises and primary and secondary schools, use a Gigabit Ethernet network to build backbone networks.

For the metropolitan area Network, the current hundred mega and Gigabit Ethernet has been widely used in the metropolitan area Network, and the next ten Kat Ethernet may become the backbone of the mainstream metropolitan area network technology.

Switching technology to break the principle of shared Ethernet, so that the size of Ethernet and coverage can be greatly improved, so that Ethernet can overcome numerous LAN technology and a solo show. The VLAN and three-layer switching technology (routing Exchange) overcomes the limit of network size in the pure two-layer switching network, further expands the coverage of the network and improves the performance, security and manageability of the network. Therefore, the three-tier exchange has been rapidly popularized in the backbone of large and medium-sized enterprises, and many small and medium sized networks have begun to introduce three-tier switching technologies, taking into account future developments.

In the past, the three-tier switch and the router is the difference between: three-tier switch using a single route, multiple forwarding, using the CPU and software for the first route of the calculation, and then the ASIC chip and other hardware according to the routing table for high-speed forwarding, the interface type is more single, mainly Ethernet, There are also fewer supported routing protocols and link protocols, and routers use CPU and software for routing, which is rich in interface types and supports more routing protocols and WAN link protocols.

The initial position of the two is that the routers are used for WAN connections, and the three-tier switch is used in the LAN core to replace the previous routers to achieve cross VLAN access. With the development of routing and switching technology, the three-layer switch is gradually developing to multi-layer exchange, such as TCP ports and DiffServ parameters above the 4th layer, which are processed by hardware. And the support of the routing protocol is extended by the initial RIP to the OSPF and even WAN Network routing protocol BGP of the large-scale network, and the interface type of the high-end routing switch, in addition to Ethernet, also begins to involve the WAN interface such as ATM and POS to meet the needs of the metropolitan area network. But the high-end router also borrows more from the route switch technology, uses the hardware to carry on the route computation, the forwarding ability also greatly enhances. Switches and routers tend to converge at the high-end, and similar devices from different vendors may be referred to as "routing switches" or "switched routers." It is also the maturity of the three-tier exchange technology, which makes the telecom operators dare to use Ethernet technology in such a large scale network as the metropolitan area network.