The Design And Implementation Of Tunnel Management Under Centralized WLAN System

With the development of WLAN and expanding network scale, the problem becomes increasingly prominent when people manage, monitor and control a large number of wireless access points in the traditional WLAN network which centers on FAT AP. Centralized WLAN architecture is a good solution to the problem.Therefore, an effective design of centralized WLAN architecture is of great significance.This paper analyzes the main problems of networking and management in traditional WLAN.A new network architecture—Wireless Controller AC and FIT AP's network program, which is centralized WLAN architecture based on the CAPWAP protocol. Then the paper briefly introduces the CAPWAP protocol that is control and provisioning of wireless access points protocol. It is a kind of tunneling protocol based on FIT AP application layer. It provides centralized WLAN management and communication standards for wireless local area network and enables multiple wireless terminals to be centralized controlled and configured.Wireless controller AC and wireless access point AP make communication by establishing two tunnels to manage software upgrade and configuration.Then, this paper proposes the CAPWAP tunnel management mechanism.Tunnel management is an important component of the centralized WLAN management. CAPWAP tunnel provides a unified channel for the management and configuration of AP and transmission control message and data packet. This paper introduces the CAPWAP tunnel management mechanism. Compared to the LWAPP tunnel management mechanism, the paper proposes CAPWAP tunnel management improvement scheme. It includes the tunnel establishment, tunnel keep-alive, tunnel restoration, the NAT traversal, the packet retransmission. After that it describes the realization of CAPWAP tunnel management mechanism to address some of the existing problems such as unstable tunuel under large traffic, NAT traversal failure and so on. Finally, the paper gives the system test results which prove it can successful realize the above CAPWAP tunuel management mechanism.