Progression of WLAN Architecture

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29 Οκτ 2013 (πριν από 3 χρόνια και 11 μήνες)

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Chapter 10

Wireless
Devices

Outline


Wireless LAN client devices


Progression of WLAN architecture


Specialty WLAN infrastructure

Wireless LAN client devices


Radio Card Formats


PCMCIA
-
type adapter (PC Card)

Wireless LAN client devices


Radio Card Formats


Mini PCI

Wireless LAN client devices


Radio Card Formats


Express Card is hardware standard that is replacing
PCMCIA cards

Wireless LAN client devices


Radio Card Formats


SD and CF card

Wireless LAN client devices


Radio Card Formats


Desktop PCI adapter

Wireless LAN client devices


Radio Card Formats


USB adapter

Wireless LAN client devices


Radio Card Chipsets


Client Utilities

Progression of WLAN Architecture


Progression of WLAN Architecture


Autonomous Access Point


Intelligent Edge
Architecture


Fat APs, stand
-
alone APs, or intelligent edge APs


All configuration settings exist in the autonomous
AP itself, and, therefore, managment and
configuration occurs at the access layer


All encryption and decryption mechanism and MAC
layer mechanisms also operate within the
autonomous AP

Progression of WLAN Architecture


Autonomous Access Point


Intelligent Edge
Architecture


Features:


Multiple managment interfaces: command line, web GUI and
SNMP


WEP, WPA and WPA2 security capabilities


WMM quality
-
of
-
service capablilities


Fixed or detachable antennas


Filtering options, such as MAC and Protocol


Connectivity modes: root, repeater, bridge, and scanner


VLAN support (VLANs are created on a managed wired
switch)

Progression of WLAN Architecture


Wireless Network Management System
(WNMS)


WNMS provides a central point of managment to
configure and maintain thousands of autonomous
APs.


WNMS can be either a hardware appliance or a
software solution


Configuration settings and firmware upgrades can
be pushed down to all the autonomous APs

Progression of WLAN Architecture


Wireless Network Management System
(WNMS)


Features


RF spectrum planning and management


Monitor and intelligent edge WLAN architecture with
arlam and notifications centralized and integrated into a
management console


Network reporting, trending, capacity planning, and
policy enforcement


Rogue AP detection


WNMS will not assist in the roaming capabilities between
APs

Progression of WLAN Architecture


Wireless Network Management System
(WNMS)

Progression of WLAN Architecture


Centralized WLAN Architecture


WLAN controller


Central WLAN controller resides in the core of network


The distribution system service (DSS) and integration
service (IS) function within the WLAN Controller


Almost all of configuration settings are configured on the
centralized WLAN Controller

Progression of WLAN Architecture


Centralized WLAN Architecture


WLAN controller function


AP management


802.11 traffic tunneling


AP group profiles


WLAN profiles


Virtual BSSIDs


VLANs


User management


Layer 2 security support


Layer 3 and 7 VPN concentrators

Progression of WLAN Architecture


Centralized WLAN Architecture


WLAN controller function (cont.)


Captive portal

(guest WLAN and guest WLAN profiles)


Automatic failover and load balancing


Internal Wireless Intrusion Dectection Systems


Dynamic RF spectrum management


Bandwidth management


Firewall capabilities


Layer 3 roaming support


Management interfaces

Progression of WLAN Architecture


Centralized WLAN Architecture


Lightweigh AP


In
the centralized WLAN architecture, autonomous APs
have been replaced with
lightweight access points
, also
know as
thin

APs


Lightweight AP has minimal intelligence
and very limited
sofware capabilities.


Security settings are configured on the WLAN controller
but some lightweight AP still handle the encryption and
decryption machanism

Progression of WLAN Architecture


Split MAC


Some of MAC services are handle by WLAN
controller, and some are handle by lightweight AP


WLAN controller


Integration service and distribution system service


WMM QoS


Lightweight AP


Encryption and decryption of 802.11 data frames


802.11 management and control frame

Progression of WLAN Architecture


Remote Office WLAN controller


Remote office WLAN controller is to allow remote
and branch offices to be managed from a single
location


Remote WLAN controller typically communicate
with a central WLAN controller across a WAN link


The central controller will download the network
configuration settings to the Remote WLAN
controller

Progression of WLAN Architecture


Distributed WLAN hybrid


Distributed
WLAN architecture that uses a WLAN
controller
that manages hybrid fat/thin access
points


QoS

policies and all of the
802.11
MAC data
forwarding is handled at the edge of the network at
the
AP instead
of back on the
WLAN controller


Unified WLAN architecture


WLAN architecture could very well take another
direction by fully integrating WLAN controller into
wired network infrastructure
devices

Progression of WLAN Architecture


Specialty WLAN infrastructure


Wireless Workgroup bridge


A wireless workgroup bridge (WGB) is a wireless device
that
provides wireless connectivity for
wired
infrastructure
devices that do not have radio cards.


The
radio card inside the WGB
associates
with an
AP and
joins the basic service set (BSS) as a client
station


Because the WGB is an associated client of the access
point, the WGB
does
not provide connectivity for other
wireless
clients

Progression of WLAN Architecture


Specialty WLAN infrastructure


Wireless LAN bridge


The
purpose of bridging is to provide wireless
connectivity between two or more wired
networks


Wireless
bridges support two major
configuration
settings:
root

and
non
-
root


A bridge link that connects only two wired networks is
known as a point
-
to
-
point (
PtP
)
bridge


A point
-
to
-
multipoint (
PtMP
) bridge link connects
multiple wired networks

Progression of WLAN Architecture


Specialty WLAN infrastructure


Enterprise Wireless Gateway


An enterprise wireless gateway (EWG) is a middleware
device used to segment autonomous
AP
from the
protected wired network
infrastructure


EWG
can segment the unprotected wireless network from
the protected wired network by
acting
as a router, a VPN
end point, and/or a firewall
.


There
is no AP management available within a
EWG


EWG does
not have an internal
WIDS,
RF spectrum
management or control.

Progression of WLAN Architecture


Specialty WLAN infrastructure


Residential Wireless
Gateway


Residential wireless gateway(RWG) is a very fancy term for a
home wireless
router


The following features are supported by a residential wireless
gateway:


Configurable 802.11 radio card


Support for simple routing protocols such as RIP


Network Address Translation (NAT)


Port Address Translation (PAT)


Port forwarding


Firewall


L2 security support (WEP or WPA1 Personal or WPA2 Personal)


DHCP server


Multiport Ethernet switch for connecting wired clients

Progression of WLAN Architecture


Specialty WLAN infrastructure


VPN Wireless
Router


Enterprise
-
class
wireless routers exist that can also
act
as
an end point for a VPN
tunnel


VPN wireless routers are typically used as
edge
router
solutions in remote or branch offices

Progression of WLAN Architecture


Specialty WLAN infrastructure


Wireless LAN Mesh
Routers


Wireless
mesh
routers communicate with each other using
proprietary layer 2 routing protocols,
creating
a
self
-
forming

and
self
-
healing

wireless infrastructure (a mesh)
over which edge devices
can communicate


A
self
-
forming

WLAN mesh network automatically
connects
access points upon installation
and
dynamically
updates routes as more clients are added.


Because
interference may occur, a
self
-
healing

WLAN
mesh network will automatically reroute data traffic in a
Wi
-
Fi mesh cell.

Progression of WLAN Architecture


Specialty WLAN infrastructure


Enterprise Encryption
Gateway


An enterprise
encryption
gateway (EEG) is an 802.11
middleware device that provides for
segmentation
and
encryption


WLAN array


A company called
Xirrus

offers a proprietary solution that
combines a WLAN controller and multiple AP in a single
hardware device known as a Wi
-
Fi Array


Up to 16 AP radios using sector antennas and an
embedded WLAN controller all reside in one device

Progression of WLAN Architecture


Specialty WLAN infrastructure


Cooperative control


Cooperative control AP (CC
-
AP) combines an
autonomous AP with a suite of cooperative control
protocols, without requiring a WLAN controller


The cooperative control protocols enable multiple CC
-
AP
to be organized into groups

Progression of WLAN Architecture


Specialty WLAN infrastructure


Virtual AP system


A virtual
AP
solution uses multiple access points that all share
a single basic service set identifier
(
BSSID) MAC
address


client stations believe they are connected to only a single
AP,
although
they may be actually roaming across multiple
AP


The main advantage is that clients
experience
a “zero handoff”
time and many of the latency issues associated
with
roaming
are
resolved


All of the AP in an Single channel architecture (SCA) transmit
on the same channel yet do not interfere with each other

Progression of WLAN Architecture


Specialty WLAN infrastructure


Real
-
time Location Systems (RTLS)


WLAN RTLS can track the location of any 802.11 radio
device as well as active Wi
-
Fi RFID tags


Active RFID tags and/or standard Wi
-
Fi devices transmit
a brief signal at regular interval, adding status or sensor
data if appropriate


The signal is received by standard AP (or RTLS sensors)
without any infrastructure changes needed, and is sent to
RTLS server


The RTLS server uses signal strength and/or time
-
of
-
arrival algorithms to determine location coordinates

Progression of WLAN Architecture


Specialty WLAN infrastructure


VoWiFi


VoWiFi

telephone


802.11 infrastructure (autonomous AP and/or WLAN
controller solution can both be used)


PBX


PBX make connections among the internal telephones of a
private company and also connect them to PSTN via trunk lines


PBX provides dial tone and may provide other features such as
voicemail


QoS

Chapter 10

The END