| With the proliferation of a large variety of mobile devices,wireless local area networks(WLANs)have evolved.The number of devices supporting WLAN is constantly expanding.For a large-scale Enterprise WLAN network,a large number of APs and wireless terminal STAs need to be managed.In the face of such a large number of APs and STAs,equipment management,operation and maintenance expenses,and data security will all be huge challenges.The WLAN AC-AP network architecture began to emerge.Wireless Access Controller,WLAN-AC equipment,centrally manage all the APs and STA devices accessing the WLAN network at one central point,complete the functions of centralized authentication,roaming and delivery,and complete the WLAN data packets centralized forwarding,to ensure data security.The thesis introduces the implement solution of WLAN-AC equipment.This implement solution adds the wireless management and forwarding functions based on the traditional Layer 3 switch.The wireless packet uses the CAPWAP tunneling protocol to complete the packet communication between the AP and the WLAN-AC equipment,and more accelerates the data-plane forwarding through Cavium’s OCTEON chip,whichi is the hardware engine to accelerate the packet processing.In the overall software system architecture,the wired control plane,the wireless control plane,and the data forwarding plane are completely decoupled to form three independent subsystems,MPU,WPU and DPU.The subsystems run completely independently and can be extended in parallel according to performance requirements and different equipment form,so that the software system architecture is a flexible expansion architecture.MPU subsystems based on the existing Layer 3 switch software,on this basis,increase CAPWAP interface management functions and synchronization the control plane results to the WPU.WPU subsystem completes WLAN wireless control plane processing to complete the entire CAPWAP protocol processing,thus supporting APs online/offline,STA online/offline,centralized authentication,centralized configuration and delivery,STA wireless roaming and other wireless control functions.The DPU subsystem processes the data plane of the WLAN-AC equipment,and it performs functions such as CAPWAP tunnel packet parsing,packet classification,wireless forwarding table lookup,forwarding to the control plane,CAPWAP tunnel packet encapsulation,traffic shaping,and bandwidth QoS.And DPU use the Cavium Octeon chip to complete packet acceleration processing to achieve the data plane performance.The thesis describes the implementation of WLAN-AC equipment software system,and performs functional testing and performance testing on WLAN-AC equipment.The resulting WLAN-AC equipment performed well in the test and meet the design requirements. |
