Vswitch Structure Type

The LAN switch has excellent performance. It comes from its unique internal technical structure. Different switching modes or different switching types are also closely related to the internal structure of LAN switches. Therefore, understanding the internal structure of a LAN switch is equivalent to understanding the technical characteristics and working principles of the LAN switch. Currently, LAN switches use the following internal technical structures. 1. Shared memory structure this structure depends on the high-performance connection of the full port provided by the central LAN switch engine. The core engine checks each input packet to determine the connection route. This method requires a lot of memory bandwidth and high management costs. Especially with the increase of LAN switch ports, the memory capacity is required to be larger and the speed is faster, and the price of central memory becomes very high, this makes the LAN switch memory a major bottleneck for performance implementation. 2. the cross-bus structure can establish direct point-to-point connections between ports. This structure provides good performance for simple single-point (Unicast) information transmission, however, it is not suitable for point-to-point Broadcast Transmission. In the actual network application environment, the broadcast and multicast transmission modes are very common, so this standard cross-bus mode will bring about some transmission problems. For example, when port A transmits data to Port D, port B and port C can only wait. When port A broadcasts messages to all ports, it may cause queuing of the target port. This will consume a large amount of system bandwidth, thus affecting the transmission performance of LAN switches. N × (N + 1) Cross bus is required to connect N ports. Therefore, the implementation cost will also increase sharply as the number of ports increases. 3. In view of the defects of the standard cross bus, a hybrid cross bus implementation method is proposed. The design idea of this method is to divide the integrated cross Bus Matrix into small cross matrices, and connect them through a high-performance bus in the middle. This structure reduces the number of Cross buses, reduces costs, and reduces bus contention. However, the bus connected to the cross matrix has become a new performance bottleneck. 4. Ring bus structure this structure supports up to four switching engines in one ring, and supports Switching Matrix interconnection at different speeds, and communication between the ring and the ring through the switching engine. Because the ring structure is used, it is easy to aggregate bandwidth. When the number of ports increases, the bandwidth increases accordingly. Different from the preceding structures, this structure has an independent control bus used to collect bus status, process routes, control traffic, and clean up the data bus. In addition, the management module can be added to the ring bus to provide complete SNMP management features. You can also select the layer-3 switching function as needed. The biggest advantage of this structure is its strong scalability, low implementation cost, and effectively avoids the bus bottleneck caused by system expansion.