The Research Of Layer3Ethernet Switch Hardware System

With the rapid development of information technology, the communication service between two subnets has been increasing exponentially. Because of the disadvantages of traditional routers, like the slow processing speed and complex configuration, they cannot meet the requirements of a large quantity of communication service across subnets and VLAN (Virtual Local Area Network), Additionally, the traditional switches operate in the second layer in the OSI (Open System Interconnection) reference model, without any capability of routing, that is to say they cannot process the data transmissions across subnets. The layer-3switching technology emerged under the circumstance. The layer-3switch operates in the3rd layer in the OSI reference model. Not only can they deal with data transmission, but also its processing speed is close to the layer-2switch.To meet the demand for the Ethernet layer-3switch and accelerate the communication between subnets, the department of business computer products in Huawei Technologies Co., Ltd. is responsible for the development of the layer-3switch which is suitable for E6000blade server for AliYun Co., Ltd.This paper relies on the projects of business computer products department in Huawei Technologies Co., Ltd. It studies the hardware design for an Ethernet layer-3switch, which integrated the gigabit,10-gigabit and stacking ports. The product exploits the microcontroller, MPC8349, multifunction, and highly-integrated and high port-density multilayer switch IC, BCM56514to construct the management and switch subsystems. The contents are stated below.Firstly, it introduces the research status and development trends, and analyzes the drawbacks of routers when dealing with a large quantity of communication across subnets, thereby specifying the significance of the research. According to the analysis of the OSI reference model, it studies the principles of a layer-2switch and a layer-3switch. Furthermore, the key technologies and main characteristics are investigated, and the related Ethernet interfaces are represented.Secondly, the hardware design is described, including the power management circuits, modules of CPLD (Complex Programmable Logic Device) logic function, debugging interfaces, temperature monitor, and fan control and so on. Thirdly, it studies the methods of anti-interference. The transmission line model and common problems, like reflection and cross-talk, are specified. According to the circuits in this paper, it analyzes the simulation results and proposes the relevant anti-interference measurements for key components and PCB design.Finally, it explains the test process of the hardware, including the function test, performance test, and system test. The results indicate that the Ethernet layer-3switch fulfills the specialized indices in national standard. Further, the products have been operating stably in core network in Huawei Technologies Co., Ltd. and AliYun (Hangzhou) Co., Ltd. for more than one year.