This MIB is intended to be implemented on all those devices operating as Central controllers, that terminate the Light Weight Access Point Protocol tunnel from Cisco Light-weight LWAPP Access Points. Link Test is performed to learn the radio link quality between AP and Client. CCX linktest is performed for CCX clients. With CCX linktest radio link can be measured in both direction i.e. AP->Client(downLink) and Client->AP(uplink). When client does not support CCX or CCX linktest fails,ping is done between AP and Client. In ping test, only uplink (client->AP) quality can be measured. The relationship between the controller and the LWAPP APs is depicted as follows. +......+ +......+ +......+ +......+ + + + + + + + + + CC + + CC + + CC + + CC + + + + + + + + + +......+ +......+ +......+ +......+ .. . . . .. . . . . . . . . . . . . . . . . . . . . . . . +......+ +......+ +......+ +......+ +......+ + + + + + + + + + + + AP + + AP + + AP + + AP + + AP + + + + + + + + + + + +......+ +......+ +......+ +......+ +......+ . . . . . . . . . . . . . . . . . . . . . . . . +......+ +......+ +......+ +......+ +......+ + + + + + + + + + + + MN + + MN + + MN + + MN + + MN + + + + + + + + + + + +......+ +......+ +......+ +......+ +......+ The LWAPP tunnel exists between the controller and the APs. The MNs communicate with the APs through the protocol defined by the 802.11 standard. LWAPP APs, upon bootup, discover and join one of the controllers and forward all the 802.11 frames to them encapsulated inside LWAPP frames. GLOSSARY Access Point ( AP ) An entity that contains an 802.11 medium access control ( MAC ) and physical layer ( PHY ) interface and provides access to the distribution services via the wireless medium for associated clients. LWAPP APs encapsulate all the 802.11 frames in LWAPP frames and sends them to the controller to which it is logically connected. Central Controller ( CC ) The central entity that terminates the LWAPP protocol tunnel from the LWAPP APs. Throughout this MIB, this entity also referred to as 'controller'. Cisco Compatible eXtensions (CCX) Wireless LAN Access Points (APs) manufactured by Cisco Systems have features and capabilities beyond those in related standards (e.g., IEEE 802.11 suite of standards, Wi-Fi recommendations by WECA, 802.1X security suite, etc). A number of features provide higher performance. For example, Cisco AP transmits a specific Information Element, which the clients adapt to for enhanced performance. Similarly, a number of features are implemented by means of proprietary Information Elements, which Cisco clients use in specific ways to carry out tasks above and beyond the standard.Other examples of feature categories are roaming and power saving. Light Weight Access Point Protocol ( LWAPP ) This is a generic protocol that defines the communication between the Access Points and the Central controller. Mobile Node ( MN ) A roaming 802.11 wireless device in a wireless network associated with an access point. Mobile Node and client are used interchangeably. Received Signal Strength Indicator ( RSSI ) A measure of the strength of the signal as observed by the entity that received it, expressed in 'dbm'. Signal-Noise Ratio ( SNR ) A measure of the quality of the signal relative to the strength of noise expressed in 'dB'. REFERENCE [1] Wireless LAN Medium Access Control ( MAC ) and Physical Layer ( PHY ) Specifications. [2] Draft-obara-capwap-lwapp-00.txt, IETF Light Weight Access Point Protocol