| As wireless point technology is widely deployed as WLAN appliance, the traditional fat AP mode is getting harder to control and rapidly deploy with more APs, so light weight AP which requires central AC to manage all the attached APs comes into beings, and in most cases, AC also is responsible for forwarding traffic centrally.This paper surrounds the subjects of how light weight is accessed and how cloud AC systems share AP loads. and an infrastructure network model is raised in order to scale the ultra large amount of APs deployed in the AC domains, the model mainly virtualize all the reference points of the datapath in which a packet flows through the AC system to satisfy the multi-tenants scenes, and in order to enhance the traffic forwarding performance, the high performance data plane development kit DPDK is used to construct a virtual switch which lives in host. The main work of this paper consist of the following aspects:(1) Wireless network customization based on OpenWrt:transferring traditional L3 forwarding function unit to central AC,Layer 2 network in APs is built instead, in order to support L2 and L3 access,respective networks are tuned to satisfy network access needs.(2) Design and implementation of virtual link based on DPDK PMD specification: two kinds of virtual links which both adapt to poll mode driver are considered in the article,they are respectively virtual vxlan pmd link for L3 ap access and virtual machine link for virtual machine access.(3) Design and implementation of multi-tenant virtual switch:vSwitch which runs in host machine leads traffic between virtual machine and physical network, moreover,vlan and link id are used for distinguishing traffic belong to different ac-ap pairs.(4) Design and implementation of virtual AC:virtual AC runs in virtual machine, and through vm pmd link,it can reach any WAN and APs network.the function of AC is to embody all the function units which exist in traditional self-contained AP,also linux namespace is used to segregate vAC entities.In summary, this paper virtualized infrastructure network to satisfy multiple tenancy and use DPDK to enhance packet forwarding performance, the performance experiment compared with traditional host virtual network show that the virtual cloud AC system can scale among multiple AP tenancy instances and improve the central forwarding capability. |
