Information with industry and SMEs in the acceleration of information, networking hot spot is shifted from the edge of the core network. Focused on the access network construction and application migration, the switch brings the market's "golden" opportunity. Among the many vendors push the edge of the network intelligence to the power market is gradually made, the switch network equipment market is being princes of concern from various quarters and favor, is expected to become the IT field has a gladiatorial combat battlefield.
Present, the commanding height of the battle is the third layer switch market, especially in the edge switch. The market survey shows that the switch has begun to go beyond the edge of the core switches, and gradually occupy the mainstream position. The user needs survey results confirm this: the user in choosing the switch, consider buying the largest factor is the application and safety, thus, many would prefer to management of a very strong three-or multi-layer switch.
Improve the traditional routing With the Internet / Intranet, and the rapid development of B / S (browser / server) computing model widely used, cross-regional, inter-networks rapid growth of business, industry and users are deeply traditional bottlenecks in the network routers effect. Therefore, the improvement of the traditional routing imminent.
In this case, a new routing technology came into being, this is the third layer switching technology. Three devices based on this technology, if called "routers" because it can operate in the network protocol of the third layer is a routing device and can be played to understand the routing decision role; if it is " switch "because it's fast, almost second tier exchange rate.
Raising the level of the user network application, is to promote large-scale application of three switches one of the main driving force.
Users are no longer satisfied with the basic functions of switches, will connect the input and output port forwarding service flow achieved, in addition to demands for an exchange, authentication, packet filtering, but also hope that the switch has a routing processing; user different applications, but also the flexibility of the network proposed new requirements.
Same time, with the rapid expansion of network scale and network applications, increasing the user network to strengthen the control of visitors to restrict unauthorized users of the communication, to ensure the security of the entire network, for example, on the campus network equipment security management, CPN security access requirements, corporate network isolation between different services. However, the common switch network can not effectively isolate the data transmission between the network, control user access to the user LAN security threats. Through all three switches are explicit or implicit policy-based VLAN classification method provides secure access mechanism to improve network security, and effectively inhibited the production of broadcast storm.
As China's enterprise network, campus network and the rapid development of broadband development, the application layer switches from the initial backbone layer, convergence layer has been penetrated into the edge of the access layer. The emergence of three switches, as Cisco router widely used in the wide area network, as will in the future for a long time to dominate the network.
Meet multimedia applications With the rapid development of Internet, the user application on the network more and more users over the network is no longer limited to data, online trading, online learning, video on demand, community theater and other users of the network are increasingly becoming practical needs, pure two-story exchange can not meet the actual needs of users. The advantage of three switches, mainly in two aspects of application and network security.
Applications, mainly in the user transmission on the network no longer limited to data, voice and video latency, jitter, multimedia information requires very high also achieved the same network transmission. Due to the general switch model in OSI7 second layer (the data link layer), the division of subnets and broadcasting restrictions provide very little control, very easily lead to network congestion, so that the packet loss and delay increase can not guarantee the quality of service. Put the three-switch two-story exchange network communication technology and three-routing (or three-forwarding) technology combines ASIC technology to achieve wire-speed through the exchange of substantially increased capacity of packet forwarding device data, to eliminate the forwarding bottleneck. At the same time through the VLAN classification, efficient multicast control, flow management and access control strategy functions effectively to ensure full utilization of network resources, and ensure applications meet the needs of various users.
The other hand, expansion of the scale with the network, the network becomes increasingly complex, network operation and management of the cost, much higher than the cost of the network equipment itself. Easy to maintain and easy management requirements, but also contributed to the widely used three-tier switch. In the past, network administrators will be 3 / 4 of the time spent in the maintenance of the network infrastructure to ensure optimal traffic flow and deal with moving and changing and so on. Typically, when a user moved to another physical location of the network, you need to re-configure the network, and even the user's workstation also needs a lot of management.