The Design And Implementation Of A Centralized CAPWAP WLAN System

With the rapid development of wireless LAN (WLAN), the extent and coverage ofthe wireless network have been expanding. Traditional wireless network was mainlybased on autonomous wireless access points (AP, Access Point) which were commonlyknown as "Fat" AP. However, the growing wireless access points, which are facingmanagement difficulties, lack of control and poor scalability issues, have becomeincreasingly unable to meet customer demand. To this end, a new centralized WLANnetwork structure has emerged and become the mainstream in the moment. This structureallows a wireless access controller (AC, Access Controller) centralized managing andcontrolling AP, and AC largely shares or replaces the function of "Fat" AP, which makesthe streamlinedAP (“thin”AP, Fit Access Point) easily to manage, control and expand.Aiming at meeting the demand of enterprise-class wireless LAN and based on theoriginal Control and Provisioning of Wireless Access Points Protocol Specificationwhich is combined with the requirements of "China Mobile WLAN_AC-AP interfaceintercommunicate specification-basic agreement", the state machine is optimized and adesign idea of the behavior of the communication between the AP and AC is offered. ACas a network entity, can manage multiple AP and coordinately share their variousbusiness of802.11, and centralized configure AP. Meanwhile, this paper makes a detaileddesign of the network packets sending mode and the form organization of AP, which canadapt to AC centralized management.Being tested in experimental network environment, Fit AP can not only achievebusiness requirements, but also accurately achieve the kinds of improvements, and Fit APfits the business requirements of large-scale WLAN network of China Mobile.