Study On Virtual Network Based On NetFPGA

Study on Virtual Network based on NetFPGAMicroprocessor has a history of nearly 40 years, during which its performance is greatly improved, and its performance is doubled every 18 months, which is known as "Moore's Law." From the original toy to now, the performance of the microprocessor has surpassed the performance of super computer cray-1. During each round of growth process, the processor can support more complex applications, which make users have higher expectations to the performance of future processor.In the past years, the need of applications was increased with the increase of the performance of processor. At first, the processor can always be able to meet the needs of applications. However, in the past few years, the situation changed. The processor itself can not meet the requirements of high performance computing, resulting in the gap between needs and performance. Many traditional applications using increasingly complex algorithms, and have more requirements to the processor. For example, to improve the communication application software, and the operations including coding and decoding, data compression and storage, encryption are more complex. Some even have the complexity of the emergence of self-excited spiral. User also wants to speed up the application software to work out the result as soon as possible, they can not bear the slow response, that they ask for new standards of the application performance. On the other hand, the competitive advantage which was caused by calculation speed also contributed to improve the current handling capacity.One solution is use hardware to accelerate the performance, using a dedicated co-processors to improve processing performance. As the basis of co-processor design, FPGA have the obvious advantages on price, performance, ease of use and power consumption. Today's FPGA has a great performance potential. They support a variable pipeline depth, providing a large number of parallel computing resource, complete a very complex functions during a single clock cycle. FPGA's programmability ensures that devices could meet the special needs of the application software, there is no cost of designing custom co-processor, and no problem of delay. FPGA is re-programmable, it can custom very flexible co-processing functions for applications in a single chip.FPGA's internal memory also has a great performance advantages. For example, co-processor chip memory means that the logic of the memory access bandwidth will not be limited by the device of I/O pin-count. Moreover, the memory and arithmetic logic are closely integrated, eliminating the need for external high-speed memory buffer. This also avoids large power buffer access and consistency problems. Using the internal memory also means we do not need more co-processor I/O pins to raise their access memory capacity, thus simplifying the design. More larger capacity FPGA has the same circuit board form factors with the original device, so we can improve performance without changing the circuit board.This paper proposed a new architecture of virtual network based on NetFPGA, making the following two changes to improve the efficiency of old virtual network:(1) We use co-processor(FPGA) and the CPU together to achieve virtual network. The new architecture will be divided into the FPGA's part and the CPU's part.(2) We use CAM to achieve reading and writing the IP entry. The CAM finds the entry by address based on hardware which could increase the ration of entry finding.This system consists of three parts:the part of NetFPGA, the part of PCI which connecting the host to the NetFPGA, the part of software no the host computer.(1) The part of NetFPGA consists of the module of MAC INPUT and the module of OUTPUT QUEUE and other module which has been developed by the student of Standford University,and the module which is developed by me to achive the virtual network.(2) The part of PCI exchange data between the host computer and the platform of the NetFPGA.(3) The part of the software on the host computer plays the role of the router management.Finally, we can conclude by the experimental data, the design of the hardware platform achieve the communications of virtual machines across local area network, the experimental data prove that the communication efficiency in the hardware is higher than the communication efficiency in software.