Research And Implementation Of Virtual Switch Based On DPDK

Network virtualization has become one of the key technologies in the development of the cloud services.The typical application of network virtualization in cloud services is to use virtual switches for isolation and communication management between tenants.At present,the industry has developed a variety of mature virtual switches.But with the dramatic increace of data traffic in the network,performance bottleneck is common in these virtual switches.It mainly displays in low data processing capability and repeated copies of memory result in kernel consumption.The main work of this thesis is based on Open vSwitch to implement a user-mode packet forwarding scheme by using Intel DPDK.Then implement VXLAN function on this basis.The thesis proposes a new packet processing scheme for the Open vSwitch.Transfer the main work of packet processing from kernel state to user state by using the driver interfaces and the underlying resource access interface provided by DPDK.Then the thesis uses KNI component to design and develop the user space protocol stack quickly.User space is mainly responsible for tunnel protocol processing.Other traditional network protocols processing is completed with the help of kernel protocol stack.Most of packet processing work transfers to user space will reduce kernel memory copy especially in the data center.In the enormous increase of packets,the scheme can reduce the occupancy of kernel resources and solve the problem of low data processing capacity.The thesis uses exclusive multicore polling mode to complete packets transceiver function.Compare to the traditional interrupt mode,the scheme avoids context switches latency cased by interrupt.Finally,the thesis implements user state VXLAN function on optimized Open vSwitch by establishing VXLAN tunnel and issuing tunnel flow table items.Finally,the test environment is built according to application scenarios.The function test and performance test are completed in this environment.The test results show that the requirement functions of the system are implemented.Besides,compared to the original Open vSwitch,the forwarding rate of VXLAN packets is improved obviously.Therefore,the research results of this thesis play an important role for the application of virtual switch in cloud service.