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