This MIB is intended to be implemented on all those
devices operating as Central Controllers (CC) that
terminate the Light Weight Access Point Protocol
(LWAPP) tunnel from Light-weight  Access Points.

Link Test is performed to learn the backhaul link 
quality between two neighboring mesh nodes.

The deployment of the controller 
(referred to as CC in the diagram), mesh nodes 
(RAP and MAP) LWAPP APs, client(MS) and NMS appear 
as follows.

 +.......+                 +.......+
 +       +                 +       +
 +  NMS  +                 +  NMS  +
 +       +                 +       +
 +.......+                 +.......+
    .                         .
 .    .                     .   .
.         .                .        .
.            .             .            .
+......+     +......+     +......+           +......+
+      +     +      +     +      +           +      +
+  CC  +     +  CC  +     +  CC  +           +  CC  +
+      +     +      +     +      +           +      +
+......+     +......+     +......+           +......+
..            .             .                 .
..            .             .                 .
.  .            .             .                 .
.    .            .             .                 .
.      .            .             .                 .
.        .            .             .                 .
+......+ +......+     +......+      +......+          +......+
+      + +      +     +      +      +      +          +      +
+  RAP + +  RAP +     +  RAP  +     +  RAP +          +  RAP +
+      + +      +     +      +      +      +          +      +
+......+ +......+     +......+      +......+          +......+
.        .              .             .                 .
.        .              .             .                 .
.        .              .             .                 .
.          .              .             .                 .
.           .              .             .                 .
+......+ +......+     +......+      +......+          +......+
+      + +      +     +      +      +      +          +      +
+  MAP + +  MS  +     +  MAP +      +  MAP +          +  MAP +
+      + +      +     +      +      +      +          +      +
+......+ +......+     +......+      +......+          +......+
.                    .                          ..    . 
. .                  .                     ..        .
.   .                .                  ..            .
.     .              .              .                .
+......+ +......+     +......+      +......+.         +......+
+      + +      +     +      +      +      +          +      +
+  MAP + +  MAP +     +  MAP +      +  MAP +          +  MS  +
+      + +      +     +      +      +      +          +      +
+......+ +......+     +......+      +......+          +......+




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 the controller pushes the 
configuration, that includes the WLAN parameters to 
the LWAPP APs. 
The APs encapsulate all the 802.11 frames from
wireless clients inside LWAPP frames and forward
the LWAPP frames to the controller.

                   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 is also referred to as 'controller'.

Mobile Station ( MS )

A roaming 802.11 wireless device in a wireless
network associated with an access point. Mobile Station
and client are used interchangeably. 

Network Management System ( NMS )

The station from which the administrator manages the
wired and wireless networks.

Mesh Node

A mesh node is defined as a physical or logical entity
in the mesh network participating in forming the mesh 
backhaul. There are two types of mesh nodes supported 
in Cisco mesh network:RAP and MAP.

Root AP (RAP)

The AP forming the bridge between a wired and a mesh
network with an Ethernet interface to the wired 
network and a 802.11 radio interface to the mesh 
network

Mesh AP (MAP).

The AP extending wireless coverage similar to a 
repeater in a mesh network and consists of a 802.11 
uplink and a 802.11 downlink. On a single-radio 
backhaul, both uplink and downlink exist on the same 
radio and are logical links only. On a multi-radio 
backhaul, they may exist on different radios.

Mesh Network

Network starting with the wireless backhaul downlink
of the RAP and all the entities below except any 
attached network to the Ethernet link of MAPs. A mesh 
network below a single RAP is also referred to as a 
'Mesh Sector'.A mesh network consists of mesh nodes. 
A single mesh network is always augmented to a single 
wired network.

Mesh Link

A logical 802.11 link between two mesh nodes. A single 
link is point-to-point. All point-to-multipoint links 
are considered as multiple mesh links. Often referred 
to as mesh backhaul link.

Mesh Backhaul

A Mesh backhaul consists of mesh nodes and mesh links 
terminating at a RAP. This necessarily creates a one-
to-one relationship between a 'mesh network', 'mesh
sector' and a 'mesh backhaul' where these terms can be 
used interchangeably.

SNR
Signal to Noise ratio on the 802.11 radio.

RSSI 
Received Signal Strength Indication (RSSI), the IEEE 802.11 
standard defines a mechanism by which RF energy is to be 
measured by the circuitry on a wireless NIC. Its value is
measured in dBm and ranges from -128 to 0.

Bridged network 
The bridged network is defined as the network(s)
attached to the Ethernet port of any MAP. There can be
multiple such networks attached to a single mesh 
network.

Mesh Node Roaming
A mesh node may change its parent mesh node naturally 
when the RF/network condition changes.Child Mesh node 
will re-associate and re-authenticate to new parent 
mesh node. Mesh Security supports two types of mesh 
node roaming:
Intra-controller roaming: LWAPP session remains and 
no LWAPP session roam is necessary
Inter-controller roaming: LWAPP session is lost and 
LWAPP session roam may be necessary

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