Objectives - La Salle | Campus Barcelona

Wireless LANs
BCMSN Module 6
BCMSN 6
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Objectives
Describe the different wireless data technologies that are currently
available
Describe wireless LANs
Distinguish WLANs from other wireless data networks
Describe similarities and differences between WLANs and wired LANs
Describe types of WLAN topologies
Describe WLAN access topologies
Explain roaming between wireless cells
Describe WLAN support for VLANs and QoS
Describe wireless mesh networking
BCMSN 6 – 1 & 2
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Wireless Data Technologies
BCMSN 6 – 1 & 2
3
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Wireless Data Technologies (Cont.)
WAN
(Wide Area Network)
MAN
(Metropolitan Area Network)
LAN
(Local Area Network)
PAN
(Personal Area
Network)
PAN
LAN
MAN
WAN
Standards
Bluetooth
IEEE 802.11a,
802.11b,
802.11g
802.16
MMDS, LMDS
GSM, GPRS,
CDMA, 2.5–3G
Speed
<1 Mbps
1–54+ Mbps
22+ Mbps
10–384 kbps
Range
Short
Medium
Medium–long
Long
Fixed, lastmile access
PDAs, mobile
phones, cellular
access
Applications
BCMSN 6 – 1 & 2
Peer to peer,
device to device
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Enterprise
networks
4
Wireless LAN (WLAN)
A WLAN is a shared
network.
An access point is a
shared device and
functions like a shared
Ethernet hub.
Data is transmitted
over radio waves.
Two-way radio
communications
(half-duplex) are used.
The same radio frequency
is used for sending and
receiving (transceiver).
BCMSN 6 – 1 & 2
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Wireless LAN Evolution
Warehousing
Retail
Health care
Education
Businesses
Home
BCMSN 6 – 1 & 2
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What Are Wireless LANs?
They are:
They are not:
Local
In building or campus for
mobile users
Radio or infrared
Not required to have RF
licenses in most countries
Using equipment owned by
customers
BCMSN 6 – 1 & 2
WAN or MAN networks
Cellular phone networks
Packet data transmission
via celluar phone networks
Cellular digital packet
data (CDPD)
General packet radio
service (GPRS)
2.5G to 3G services
7
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Similarities Between WLAN and LAN
A wireless LAN is an 802 LAN.
Transmits data over the air vs. data over the wire
Looks like a wired network to the user
Defines physical and data link layer
Uses MAC addresses
The same protocols/applications run over both WLANs
and LANs.
IP (network layer)
IPSec VPNs (IP-based)
Web, FTP, SNMP (applications)
BCMSN 6 – 1 & 2
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Differences Between WLAN and LAN
WLANs use radio waves as the physical layer.
WLANs use CSMA/CA instead of CSMA/CD to access the network
Radio waves have problems that are not found on wires.
Connectivity issues
Coverage problems
Multipath issues
Interference, noise
Privacy issues
WLANs use mobile clients.
No physical connection
Battery-powered
WLANs must meet country-specific RF regulations.
BCMSN 6 – 1 & 2
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More on CSMA/CA
CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance)
The wireless 802.11 standard uses CSMA/CA or "collision avoidance."
The method is used because the wireless stations have no way to
detect collisions WHILE sending.
Attempts to avoid collisions rather than detect them
How it works:
Transmitting device listens to the network (senses the carrier) and
waits for it to be free
Device then waits a random period of time and transmits.
If the receiver gets the frame intact, it sends back an ACK to the
sender.
If no ACK is received, the message is re-transmitted.
If the channel is not clear, the node waits for a randomly chosen period
of time (backoff factor), and then checks again to see if the channel is
clear.
BCMSN 6 – 1 & 2
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Wireless LAN
Topologies
BCMSN 6 – 1 & 2
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Wireless LAN Topologies
Wireless client access
Mobile user connectivity
Wireless bridging
LAN-to-LAN connectivity
Wireless mesh networking
Combination of bridging and
user connectivity
BCMSN 6 – 1 & 2
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WLAN and LAN
BCMSN 6 – 1 & 2
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Service Set Identifier (SSID)
SSID is used to logically
separate WLANs.
The SSID must match on
client and access point.
Access point can broadcast
SSID in beacon.
Client can be configured
without SSID.
BCMSN 6 – 1 & 2
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Association Process (Active Scanning)
Steps to Association:
Client Sends Probe
AP Sends Probe Response
Client Evaluates AP
Response, Selects Best AP
Client Sends Authentication
Request to Selected AP (A)
AP A Confirms Authentication
and Registers Client
Client Sends Association
Request to Selected AP (A)
AP A Confirms Association
and Registers Client
BCMSN 6 – 1 & 2
15
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WLAN Access Topology
BSA (Basic Service Area) or microcell
ESA (Extended Service Area)
Area of radio frequency coverage
provided by an AP
Range of cells
BCMSN 6 – 1 & 2
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Wireless Repeater Topology
Overlapping 50%
The SSID of the root AP must be configured on the repeater AP
BCMSN 6 – 1 & 2
17
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Workgroup Bridge Topology
Cisco Aironet Workgroup Bridge (WGB)
Connects to the Ethernet port of a device that does not have a
WLAN NIC
Provides a single MAC address connection into an AP and
onto the LAN backbone
Only operates with
Cisco APs
BCMSN 6 – 1 & 2
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Alternative Peer-to-Peer Topology
Peer-to-Peer Configuration
(Ad Hoc Mode)
BCMSN 6 – 1 & 2
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Service Sets & Modes
Ad hoc mode
Independent Basic Service Set
(IBSS)
Mobile clients connect directly
without an intermediate AP.
Infrastructure mode
Basic Service Set (BSS)
Mobile clients use a single AP
for connecting to each other
or to wired network resources.
Extended Services Set (ESS)
Two or more Basic Service
Sets are connected by a
common distribution system
(DS).
BCMSN 6 – 1 & 2
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WLAN Features
BCMSN 6 – 1 & 2
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Roaming Through Wireless Cells
The user can move anywhere that the RF coverage permits.
Benefits
Users maintain connection while moving around
Superior power management --> better battery life
Dynamic load balancing
distributes users among Aps
APs with overlapping
coverage cells and
redundant switches
provide fault-tolerant
WLANs
BCMSN 6 – 1 & 2
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Client Roaming
Maximum data
retry count
exceeded
Too many
beacons missed
Data rate shifted
Periodic intervals
Roaming without interruption requires the same SSID on all APs.
Roaming is initiated by the client
Searches for another AP with the same SSID
Sends a reauthentication request to the new AP
BCMSN 6 – 1 & 2
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Layer 2 vs. Layer 3 Roaming
L2 Roaming
Roaming between APs that reside on a single IP subnet
Managed by the APs using mcast packets that inform the
switches that the device has moved
Inter Access Point Protocol
L3 Roaming
Roaming between APs that reside in different IP subnets
1st generation: Mobile IP
Modern WLAN implementation: lightweight APs in combination
with WLAN controllers
BCMSN 6 – 1 & 2
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Wireless VLAN Support
Multiple SSIDs
Multiple security
types
Support for
multiple VLANs
from switches
802.1Q trunking
protocol
BCMSN 6 – 1 & 2
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Wireless VLAN Support (Cont.)
VLANs propagate
across APs.
VLAN numbers are
unique.
Autonomous Aps
handle up to 16
VLANs.
BCMSN 6 – 1 & 2
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Enterprise Voice Architecture
IP phone networks can be extended with Wireless IP
phones.
802.11e specifies QoS for WLANs.
BCMSN 6 – 1 & 2
27
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Autonomous or Lightweight?
Most Cisco wireless access points/bridges are available
as autonomous or lightweight devices.
Lightweight APs use Lightweight Access Point Protocol
(LWAPP) and must have a LAN controller to function
within the network.
Autonomous APs can be configured via Cisco IOS or
may operate with the CiscoWorks Wireless LAN
Solution Engine (WLSE).
Most Cisco autonomous APs can be software upgraded
to function as lightweight APs.
BCMSN 6 – 1 & 2
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Mesh Networks
BCMSN 6 – 1 & 2
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Wireless Mesh Networking
In a mesh network topology, devices are connected with
redundant connections between nodes.
Each node needs to transmit only as far as the next node.
Paths through the mesh network can change in response
to traffic loads, radio conditions, traffic prioritization…
BCMSN 6 – 1 & 2
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Wireless Mesh Solution Components
Cisco Wireless
Control Systems
Cisco Wireless
LAN Controller
Root Access
Point “RAP”
Mesh Access
Point “MAP”
• Wireless Mesh
management
system
• Enables
network-wide
policy
configuration
and device
management
• Supports SNMP
and Syslog
• Links the
wireless Mesh
APs to the
wired network
• Handles RF
algorithms and
optimization
• Seamless L3
mobility
• Provides
security and
mobility mgt
• Serves as
“Root” or
“Gateway” AP
to the wired
network
• Typically
located on rooftops or towers
• Connects up to
32 “Pole-top”
APs using
802.11a
• Provides
802.11b/g client
access
• Connects to Root
AP via 802.11a
• Takes AC or DC
power; PoE
capable
• Ethernet port for
connecting
peripheral
devices
BCMSN 6 – 1 & 2
31
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Mesh AP Roles
Mesh APs automatically
establish connection
to Controller
Root AP (RAP) via wired
connection
Mesh AP (MAP) via selfconfiguring backhaul connection
Mesh AP uses Cisco’s
Adaptive Wireless Path
Protocol “AWPP” to
establish best path to the
Root AP
AP authenticates to Controller
and downloads configuration
and radio parameters
BCMSN 6 – 1 & 2
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Dual Radios
2.4 GHz for client access
5 GHz for backhaul
BCMSN 6 – 1 & 2
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Adaptive Wireless Path Protocol (AWP)
Adaptive Wireless Path
(AWP) protocol
establishes an optimal
path to root.
Each access point carries
feasible successor or
successors if topology or
link health changes.
AWP uses a “parent
sticky” value to mitigate
route flaps.
BCMSN 6 – 1 & 2
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Why Mesh Technology?
Enterprise Mesh
Municipal Mesh
Service Provider
Moving Indoor
Wi-Fi Outside
State, County
and City
Managed
Wi-Fi Services
• Universities and
healthcare
Extending Wi-Fi coverage
throughout the entire campus
• Hospitality
Outdoor mesh can open up
new hospitality markets
(EMEA)
• Manufacturing—
shipping and receiving
Inventory applications, handheld scanner, RFID, etc.
• Wireless bridging
P2P/P2MP links between
buildings
BCMSN 6 – 1 & 2
• Public safety/homeland
defense
Police, fire and 1st
responders
Wireless infrastructure,
vehicles and clients
• “Hot Zones”
Extend the existing “Hot
Spots” into “Hot Zones”
covering high traffic
outdoor areas
• Wireless ISPs
• Wireless access for
fixed applications
Video surveillance, sensors
Competitive last-mile access
providers using Wi-Fi for
broadband service
• Cable operators
• Public service
Hot Spot access for city
workers, utilities, inspectors
Extend the network offering
beyond the cable plant
• Digital divide and
economic development
Wi-Fi broadband access in
under-served communities
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WLAN Technology
Standards
BCMSN 6 – 1 & 2
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Unlicensed Frequency Bands
ISM: Industry, Scientific, and
Medical frequency band
UNII: Unlicensed National
Information Infrastructure band
No license required Best effort
No exclusive use Interference possible
BCMSN 6 – 1 & 2
37
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Radio Frequency Transmission
Radio frequencies are radiated into the air via an
antenna, creating radio waves.
Radio waves are absorbed when they are propagated
through objects (e.g. walls).
Radio waves are reflected by objects (e.g. metal
surfaces).
This absorption and reflection can cause areas of low
signal strength or low signal quality.
BCMSN 6 – 1 & 2
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Radio Frequency Transmission
Higher data rates have a shorter transmission range.
The receiver needs more signal strength and better SNR to
retrieve information.
Higher transmit power results in greater distance.
Higher frequencies allow higher data rates.
Higher frequencies have a shorter transmission range.
BCMSN 6 – 1 & 2
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WLAN Regulation and Standardization
Regulatory agencies
FCC – Federal Communications Comission
(United States)
ETSI – European Telecommunications
Standards Institute (Europe)
Standardization
IEEE 802.11
http://standards.ieee.org/getieee802/
Certfication of equipment
Wi-Fi Alliance certifies interoperability between products.
Certifications include 802.11a, 802.11b, 802.11g, dual-band
products, and security testing.
Certified products can be found at http://www.wi-fi.org.
BCMSN 6 – 1 & 2
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802.11b
BCMSN 6 – 1 & 2
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802.11b Standard
Standard was ratified in September 1999
Operates in the 2.4-GHz band
Specifies Direct Sequence Spread Spectrum (DSSS)
Specifies four data rates up to 11 Mbps
1, 2, 5.5, 11 Mbps
Provides specifications for vendor interoperability (over
the air)
Defines basic security, encryption, and authentication
for the wireless link
Is the most commonly deployed wireless LAN standard
BCMSN 6 – 1 & 2
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2.4-GHz Channels
Channel
Identifi
er
BCMSN 6 – 1 & 2
Channel
Center
Frequency
Channel
Frequency
Range [MHz]
Regulatory Domain
Americas
Europe, Middle
East, and
Asia
Japan
1
2412 MHz
2401 – 2423
X
X
X
2
2417 MHz
2406 – 2428
X
X
X
3
2422 MHz
2411 – 2433
X
X
X
4
2427 MHz
2416 – 2438
X
X
X
5
2432 MHz
2421 – 2443
X
X
X
6
2437 MHz
2426 – 2448
X
X
X
7
2442 MHz
2431 – 2453
X
X
X
8
2447 MHz
2436 – 2458
X
X
X
9
2452 MHz
2441 – 2463
X
X
X
10
2457 MHz
2446 – 2468
X
X
X
X
11
2462 MHz
2451 – 2473
X
X
12
2467 MHz
2466 – 2478
X
X
13
2472 MHz
2471 – 2483
X
X
14
2484 MHz
2473 – 2495
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X
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2.4-GHz Channel Use
Each channel is 22 MHz wide.
North America: 11 channels
Europe: 13 channels
There are three nonoverlapping channels: 1, 6, 11.
Using any other channels will cause interference.
Three access points can occupy the same area.
BCMSN 6 – 1 & 2
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802.11b/g (2.4 GHz) Channel Reuse
3 nonoverlapping channels available within 802.11b and 802.11g
Goal: reduce the overlapping of cells that are on the same channel
BCMSN 6 – 1 & 2
45
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802.11b Access Point Coverage
WLAN clients can shift data rates while moving
without any interaction from the user
on a transmission-by-transmission basis
Higher data rates require stronger
signals at the receiver
Wireless clients always try to
communicate with the highest
possible data rate
The client reduces the data rate only if transmission errors
and retries occur
BCMSN 6 – 1 & 2
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802.11a
BCMSN 6 – 1 & 2
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802.11a Standard
Standard was ratified September 1999
Operates in the 5-GHz band
Uses orthogonal frequency-division multiplexing
(OFDM)
Uses eight data rates of up to 54 Mbps
6, 9, 12, 18, 24, 36, 48, 54 Mbps
Has from 12 to 23 nonoverlapping channels (FCC)
Has up to 19 nonoverlapping channels (ETSI)
Regulations different across countries
Transmit (Tx) power control and dynamic frequency selection
required (802.11h)
BCMSN 6 – 1 & 2
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Understanding the 5 GHz Spectrum
5 GHz
UNII Band
5.15
5.25
4 Ch
5.35
5.470
4 Ch
5.725
5.825
11 Ch
4 Ch
UNII-3
30dBm
US (FCC)
UNII-1 UNII-2
17dBm 24dBm
To Be Defined
Europe
23dBm
30dBm
UNII-1: Indoor Use, Antenna Must Be Fixed to the Radio
UNII-2: Indoor/Outdoor Use, Fixed or Remote Antenna
(Must Implement 802.11h After Jul 19, 2007)
UNII-3: Indoor/Outdoor; Fixed, Pt-to-Pt Can Employ Higher Gain Antenna
Europe: Must Implement 802.11h
BCMSN 6 – 1 & 2
49
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IEEE 802.11h
Spectrum Management
Primary use of 5 GHz bands outdoors is radar in many
countries.
802.11h is an addition to the 802.11 family of standards.
802.11h rules are designed to minimize interference.
Uses Dynamic Frequency Selection (DFS) and Transmit
Power Control (TPC).
DFS detects the presence of other devices on a channel and
automatically switches the network to another channel if and
when such signals are detected
TPC reduces the RF output power of each network transmitter to
a level that minimizes the risk of interference to and from other
systems, while still allowing satisfactory network performance.
Radios must comply to benefit from 11 new channels.
BCMSN 6 – 1 & 2
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802.11a Channel Reuse
802.11h DFS not
available
Manual channel
assignment required
802.11h DFS
implemented
Channel assignment done
by Dynamic Frequency
Selection (DFS)
Only frequency bands can
be selected
BCMSN 6 – 1 & 2
51
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802.11g
BCMSN 6 – 1 & 2
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802.11g Standard
Standard was ratified June 2003
Operates in the 2.4-GHz band as
802.11b
Same three nonoverlapping channels: 1,
6, 11
DSSS (CCK) and OFDM
transmission
12 data rates of up to 54 Mbps
1, 2, 5.5, 11 Mbps (DSSS / 802.11b)
6, 9, 12, 18, 24, 36, 48, 54 Mbps
(OFDM)
Full backward compatiblity to
802.11b standard
BCMSN 6 – 1 & 2
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802.11g Protection Mechanism
Problem: 802.11b stations cannot decode 802.11g radio
signals.
802.11b/g AP communicates with
802.11b clients with max. 11 Mbps.
802.11b/g AP communicates with
802.11g clients with max. 54 Mbps.
802.11b/g AP activates RTS/CTS to
avoid collisions when 802.11b
clients are present.
Additonal overhead reduces
throughput.
BCMSN 6 – 1 & 2
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802.11
Standards
Comparison
BCMSN 6 – 1 & 2
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802.11 RF Comparison
802.11b – 2.4 GHz
Most commonly
deployed WLAN
standard
802.11g – 2.4 GHz
802.11a – 5 GHz
Pro
Higher throughput
Highest throughput
OFDM technology
reduces multipath
issues
OFDM technology
reduces multipath
issues
Provides up to 23
nonoverlapping
channels
Interference and noise
from other services in
the 2.4-GHz band
Con
Only 3 nonoverlapping
channels
Distance limited by
multipath issues
BCMSN 6 – 1 & 2
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Interference and noise Lower market
from other services in
penetration
the 2.4GHz band
Only 3 nonoverlapping
channels
Throughput degraded
in the presence of
802.11b clients
56
802.11 Standards Comparison
802.11b
802.11g
802.11a
Ratified
1999
2003
1999
Frequency band
2.4 GHz
2.4 GHz
5 GHz
3
3
Up to 23
No of nonoverlapping
channels
Transmission
DSSS
DSSS
Data rates [Mbps]
1, 2, 5.5,
11
1, 2, 5.5,
11
Throughput
Up to 6
[Mbps]
BCMSN 6 – 1 & 2
OFDM
OFDM
6, 9, 12, 18, 24, 6, 9, 12, 18, 24,
36, 48, 54
36, 48, 54
Up to 22
Up to 28
57
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WLAN Industry Standards
Network Radio Speeds
IEEE 802.11n
Multichannel
Greater Than 100 Mbps
IEEE 802.11g
2.4 GHz—OFDM
Up to 54 Mbps
IEEE 802.11a
5 GHz—OFDM
Up to 54 Mbps
IEEE 802.11b
2.4 GHz—DS
Up to 11 Mbps
Proprietary
1999
BCMSN 6 – 1 & 2
IEEE 802.11a/b
Ratified
2000
2001
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2002
2003
2004
2005
2006
2007
58
Range Comparisons
BCMSN 6 – 1 & 2
59
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Ratified IEEE 802.11 Standards
802.11: WLAN 1 and 2 Mbps at 2.4 GHz
802.11a: WLAN 54-Mbps at 5 GHz
802.11b: WLAN 11-Mbps at 2.4 GHz
802.11d: Multiple regulatory domains
802.11e: Quality of Service
802.11f: Inter-Access Point Protocol (IAPP)
802.11g: WLAN 54-Mbps at 2.4 GHz
802.11h: Dynamic Frequency Selection (DFS)
Transmit Power Control (TPC) at 5 GHz
802.11i: Security
802.11j: 5-GHz channels for Japan
BCMSN 6 – 1 & 2
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WLAN Security
BCMSN 6 – 1 & 2
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Why WLAN Security?
Wide availability and low cost of
IEEE 802.11 wireless equipment
802.11 standard ease of use and
deployment
Availability of sniffers
Statistics on WLAN security
Media hype about
hot spots, WLAN hacking,
war driving
Nonoptimal implementation of
encryption in standard Wired
Equivalent Privacy (WEP)
encryption
Authentication vulnerability
BCMSN 6 – 1 & 2
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Wireless LAN Security Threats
BCMSN 6 – 1 & 2
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Mitigating the Threats
Control and Integrity
Authentication
Privacy and
Confidentiality
Encryption
Ensure that legitimate Protect data as it is
clients associate
transmitted and
with trusted APs.
received.
BCMSN 6 – 1 & 2
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Protection and
Availability
Intrusion Detection
System (IDS)
Track and mitigate
unauthorized
access and
network attacks.
64
Evolution of Wireless LAN Security
Initial
(1997)
Interim
(2001)
Interim
(2003)
Encryption
(WEP)
802.1x EAP
Wi-Fi Protected
Access (WPA)
No strong
authentication
Static,
breakable keys
Not scalable
Present
Wireless IDS
Identification
and protection
against
attacks, DoS
Dynamic keys
Standardized
Improved
encryption
Improved
encryption
User
authentication
802.1x EAP
(LEAP, PEAP)
Strong, user
authentication
(e.g., LEAP,
PEAP, EAPFAST)
RADIUS
MIC
AES strong
encryption
TKIP
Authentication
IEEE 802.11i
WPA2 (2004)
Dynamic key
management
BCMSN 6 – 1 & 2
65
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Wireless Client Association
1. APs send out beacons announcing
SSID, data rates and other
information.
2. Client scans all channels.
3. Client listens for beacons and
responses from APs.
4. Client associates to AP with strongest
signal.
5. Client will repeat scan if signal
becomes low to reassociate to another
AP (roaming).
6. During association SSID, MAC
address and security settings are sent
from the client to the AP and checked
by the AP.
BCMSN 6 – 1 & 2
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WPA and WPA2 Authentication
BCMSN 6 – 1 & 2
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WPA and WPA2 Encryption
BCMSN 6 – 1 & 2
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Wi-Fi Protected Access
What are WPA and WPA2?
Authentication and encryption
standards for Wi-Fi clients and
APs
802.1x authentication
WPA uses TKIP encryption
WPA2 uses AES block cipher
encryption
Which should I use?
Gold, for supporting NIC/OSs
Silver, if you have legacy clients
Lead, if you absolutely have no
other choice.
BCMSN 6 – 1 & 2
Gold
WPA2/802.11i
• EAP-Fast
• AES
Silver
WPA
• EAP-Fast
• TKIP
Lead
Dynamic WEP
• EAP-Fast/LEAP
• VLANs + ACLs
69
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WLAN Security Summary
Enhanced Security
Basic Security
Open Access
No Encryption,
Basic Authentication
Public “Hotspots”
Remote Access
BCMSN 6 – 1 & 2
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40-bit or 128-bit Static
WEP Encryption, WPA
802.1x, 802.11i,
Mutual Authentication,
Scalable Key Mgmt., Etc.
Home Use
Enterprise
Virtual
Private
Network
(VPN)
Business
Traveler,
Telecommuter
70
Security Evaluation
Evaluate effectiveness of encrypted WLAN statistics.
Focus on proper planning and
implementation.
Estimate potential security threats
and the level of security needed.
Evaluate amount of WLAN traffic
being sent when selecting security methods.
Evaluate tools and options applicable
to WLAN design.
BCMSN 6 – 1 & 2
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Identifying and
Installing WLAN
Client Adapters
BCMSN 6 – 1 & 2
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Cisco 802.11a/b/g WLAN Client Adapters
CardBus or PCI card
Supports all three current standards
Supported operating systems
Windows 2000 and Windows XP
3 Components:
Radio + Antenna + LEDs
Drivers must be installed
Client Utilities
ADU: Aironet Desktop Utility
ACM: Aironet Client Monitor
ACAU: Aironet Client Administration Utility
BCMSN 6 – 1 & 2
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Cisco Aironet Desktop Utility Installation
BCMSN 6 – 1 & 2
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Install Cisco Aironet Site Survey Utility
BCMSN 6 – 1 & 2
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75
Choose Configuration Tool
BCMSN 6 – 1 & 2
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Reboot!
After the installation process completes, you will be
prompted to reboot your machine.
It is strongly recommended that you reboot your
machine.
After rebooting the Windows “Found New Hardware”
utility may appear. Click through the screens to allow
the wizard to install the software for the adapter.
If your network does not use DHCP, you will need to
configure your adapter with appropriate IP parameters.
BCMSN 6 – 1 & 2
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Using ADU
BCMSN 6 – 1 & 2
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ADU – Current Status
BCMSN 6 – 1 & 2
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ADU: Profile Management
Create up to16 profiles.
Set auto profile selection and weight the profiles
Scan the card to get a list of all open SSIDs
BCMSN 6 – 1 & 2
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80
ADU: Security Settings
WPA/WPA2 support.
AES and EAP-FAST (Extensible Authentication Protocol –
Flexible Authentication via Secure Tunneling) supported.
BCMSN 6 – 1 & 2
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ADU Diagnostics: Advanced Statistics
Used predominately during troubleshooting
BCMSN 6 – 1 & 2
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ADU Diagnostics: Adapter Information
Driver version
Adapter MAC
address
BCMSN 6 – 1 & 2
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ADU Troubleshooting
BCMSN 6 – 1 & 2
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Other
Features
BCMSN 6 – 1 & 2
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Cisco Aironet System Tray Utility
Associated with
Excellent/Good
Connection
Associated with
Fair Connection
Associated with
Poor Connection
Radio Disabled
Associated not
authenticated
Not associated
BCMSN 6 – 1 & 2
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86
Cisco Aironet Site Survey Utility
BCMSN 6 – 1 & 2
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87
Cisco Aironet Site Survey Utility (Cont.)
BCMSN 6 – 1 & 2
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88
Windows XP WLAN Configuration
BCMSN 6 – 1 & 2
89
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Comparison of Windows XP and Cisco
ADU
BCMSN 6 – 1 & 2
Feature
Windows XP
Cisco ADU
Configuration Parameters
Limited
Extensive
Create profiles
Yes
Yes
Enable/disable radio
No
Yes
Static WEP
Yes
Yes
LEAP
No
Yes
EAP-TLS or PEAP
Yes
Yes
Status window
Limited
Extensive
Troubleshooting
No
Yes
Statistics
No
Yes
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90
Aironet Client Administration Utility
(ACAU)
Creates file with profiles and settings
Profiles imported during the installation of ADU and firmware
For AIR-CB21AG and AIR-PI21AG
Installs across network
Encrypted setup files
Windows 2000 and
Windows XP only
BCMSN 6 – 1 & 2
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Easy binary
configurations
for security
and utility
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Cisco Wireless IP Phone
For workers who need to communicate
while moving about their workplace or
campus
Same features as Cisco wired IP Phones
Graphical, menu-driven user interface
Multiline appearance (up to six
extensions)
Phone book with speed dials
LEAP security
Auto VLAN configuration and
Cisco CallManager registration
BCMSN 6 – 1 & 2
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Cisco Compatible Extensions (CCX)
No-cost licensing of technology for use in WLAN
adapters and devices
Independent testing to ensure interoperability with
Cisco infrastructure
Marketing of compliant products by Cisco and product
suppliers under “Cisco Compatible” brand
BCMSN 6 – 1 & 2
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Cisco Compatible Extensions Features
V1
Security
VLANs and QoS
WEP
IEEE 802.1x
LEAP
Cisco TKIP
Multiple
SSIDs/VLANs
on AP
V2
V3
WPA2
EAP-FAST
NAC (wireless)
EAP-TLS
PEAP-MSCHAP
eDCF
Wi-Fi Multimedia
(WMM)
MBSSID
BCMSN 6 – 1 & 2
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Call Admission
Control (CAC)
U-APSD
TSPEC CAC
Voice metrics
Voice over IP
Performance and
Management
V4
PEAP-GTC
WPA
AP-assisted
roaming
CCKM with
LEAP
RF scanning
and reporting
Transmit
power sync
CCKM with EAPFAST
Proxy ARP
information
element
Single sign-on:
LEAP, EAP-FAST
CCKM with other EAP
types
AP-directed roaming
Location
Keep Alive link test
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Implementing
Wireless LANs
BCMSN 6 – 1 & 2
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Cisco WLAN Implementation
Cisco offers 2 “flavors” of wireless solutions:
Distributed WLAN solution
Autonomous AP
Wireless LAN Solution Engine (WLSE)
Centralized WLAN solution
Lightweight AP
Wireless LAN Controller (WLC)
BCMSN 6 – 1 & 2
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Distributed WLAN Solution Components
Autonomous access points
Network Infrastructure
Wireless Domain Services
(WDS) – optional
Wireless LAN Solution
Engine (WLSE) – optional
Acess Control Server
(ACS) – optional
RADIUS/TACACS+ security
BCMSN 6 – 1 & 2
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Centralized WLAN Solution Components
Lightweight access points
Network Infrastructure
Wireless LAN controller
(WLC) – required
Wireless Control System
(WCS) – optional
Location appliance –
optional
Acess Control Server
(ACS) – optional
RADIUS/TACACS+ security
BCMSN 6 – 1 & 2
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Cisco Centralized WLAN Model
BCMSN 6 – 1 & 2
99
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Why Lightweight APs?
A WLAN controller system is used to create and
enforce policies across many different lightweight APs.
With centralized intelligence, functions essential to
WLAN operations such as security, mobility, and quality
of service (QoS), can be efficiently managed across an
entire wireless enterprise.
Splitting functions between
the AP and the controller,
simplifies management,
improves performance, and
increases security of large
WLANs
BCMSN 6 – 1 & 2
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Wireless LAN Solution Comparison
Distributed Solution
Centralized
Solution
Autonomous
access points
Lightweight access
points
Wireless Domain
Services (WDS)
WLAN controller
WLAN Solution
Engine (WLSE)
WLAN Control
System (WCS)
PoE switches,
routers
PoE switches,
routers
DHCP, DNS, AAA
DHCP, DNS, AAA
BCMSN 6 – 1 & 2
101
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LWAPP
BCMSN 6 – 1 & 2
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Layer-2 LWAPP Architecture
L2 LWAPP is in an Ethernet frame
APs don’t require IP addressing
The controllers and the AP must be in the same broadcast
domain and IP subnet
L2 LWAPP was the first step in the evolution of the architecture;
many current products do not support this functionality
BCMSN 6 – 1 & 2
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Layer-3 LWAPP Architecture
L3 LWAPP is in a UDP/IP frame
APs require IP addressing
APs can communicate w/ WLC across routed boundaries
L3 LWAPP is more flexible than L2 LWAPP and all products
support this LWAPP operational ‘flavor’
BCMSN 6 – 1 & 2
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Association of AP to WLAN Controller
APs use LWAPP in L2 and L3 mode to associate to the
WLAN controller.
In L3 mode, the AP sends an LWAPP Discovery
Request to the controller management IP address via a
directed broadcast.
The controller responds with a Discovery Response
from the manager IP address that includes the number
of APs currently associated to the AP manager
interface.
The AP chooses the AP manager IP address with the
leas number of APs and sends the Join Request.
All subsequent communication is to the WLAN
controller AP manager IP address.
BCMSN 6 – 1 & 2
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Cisco Unified
Wireless Network
BCMSN 6 – 1 & 2
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Cisco Unified Wireless Network
Unified Advanced Services
Unified cellular and Wi-Fi VoIP. Advanced threat
detection, identity networking, location-based
security, asset tracking and guest access.
World-Class Network Management
Same level of security, scalability, reliability, ease of
deployment, and management for wireless LANs as
wired LANs.
Network Unification
Integration into all major switching and routing
platforms. Secure innovative WLAN controllers.
Mobility Platform
Ubiquitous network access in all environments.
Enhanced productivity. Proven platform with large
install base and 63% market share. Plug and Play.
Client Devices
90% of Wi-Fi silicon is Cisco Compatible Certified.
“Out-of-the-Box” wireless security.
BCMSN 6 – 1 & 2
107
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Cisco Unified Wireless Network Components
Unified Advanced Services
Cisco
Self-Defending
Network
Unified built-in support of leading-edge applications,
not an afterthought. Cisco Wireless Location
Appliance, Cisco WCS, SDN, NAC, Wi-Fi phones, and
RF firewalls.
World-Class Network Management
World Class NMS that visualizes and helps secure your
air space. Cisco Wireless Control System (WCS).
Network Unification
Seamless network infrastructure across a range of
platforms. Cisco 4400 and 2000 Wireless LAN
Controllers. Future Cisco Catalyst 6500, Series WiSM,
ISR, and 3750 integration.
Mobility Platform
APs dynamically configured and managed through
LWAPP. Cisco Aironet Access Points: 1500, 1300,
1240AG, 1230AG, 1130AG, and 1000. Bridges: 1400
and 1300.
Client Devices
Secure clients that work out of the box. Cisco
Compatible client devices & Cisco Aironet clients.
BCMSN 6 – 1 & 2
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Cisco Mobility Access Platforms
Indoor Access Points
Mobility Platform
Features
Industry’s best range and throughput
1130AG
10x0
1121G
Indoor Rugged Access Points
Enterprise class security
Many configuration options
Simultaneous air monitoring and traffic
delivery
Wide area networking for outdoor areas
Benefits
1240AG
1230AG
Zero touch management
Outdoor Access Points/Bridges
No dedicated air monitors
Supports all deployment scenarios
(indoor and outdoor)
Ease of use policy based management
1500
BCMSN 6 – 1 & 2
1400
1300
109
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Power over
Ethernet
BCMSN 6 – 1 & 2
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Power over Ethernet (PoE)
Sending operating power over Category 5 Ethernet
cable
Power Sourcing Equipment (PSE)
Switches, power injector
Powered devices (PD)
Access points, IP phones
Up to 15.4W power per port
Distances up to 100 meters
Alternative: AC power adapter
BCMSN 6 – 1 & 2
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PoE Delivery
Detection of power requirements
IEEE 802.3af
Cisco proprietary inline power
Two approved methods for “inserting” power into
Ethernet cable:
Pair 1,2 & 3,6
BCMSN 6 – 1 & 2
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Pair 4,5 & 7,8
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MidSpan Power Injection
Uses pairs 4,5 & 7,8
Requires 8-wire cabling
Does not extend 100-m total
length limit
Not possible for 1000TX
BCMSN 6 – 1 & 2
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Power Sourcing Equipment
Power injector
AIR-PWRINJ3/AIR-PWRINJ-FIB
Powering switch
Cisco Catalyst 3560-PS/3750-PS
Cisco Express CE500-LC/CE500-PC
Cisco Catalyst 4500/6500 switch with inline power line cards
Router module NM-16ESW-PWR
Router card HWIC-4ESW-POE
Router with PoE support
BCMSN 6 – 1 & 2
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PoE Switch
PoE interface configuration
switch(config-if)# power inline {auto | never}
Display PoE statistics
switch# show power inline [interface]
switch# show power inline
Available:370.0(w) Used:61.6(w) Remaining:308.4(w)
Interface Admin Oper
Power
Device
Class Max
(Watts)
--------- ------ ------ ------- ---------- ----- ---Gi0/1
auto
off
0.0
n/a
n/a
15.4
Gi0/2
auto
on
15.4
Ieee PD
3
15.4
Gi0/3
auto
off
0.0
n/a
n/a
15.4
Gi0/4
auto
on
15.4
Ieee PD
3
15.4
Gi0/5
auto
off
0.0
n/a
n/a
15.4
BCMSN 6 – 1 & 2
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Antennas
BCMSN 6 – 1 & 2
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What is the role of an antenna in the WLAN?
An antenna is a device used to transmit or receive
signals.
Antennas convert electrical energy into radio frequency
(RF) waves when it transmits, or RF waves into
electrical energy when it receives.
The size and shape of antennas are determined
primarily by the frequency of the signal they are
designed to receive. A high gain antenna is highly
focused, whereas a low gain antenna receives or
transmits over a wide angle.
An antenna provides the wireless system with three
fundamental properties: gain, direction, and
polarization.
BCMSN 6 – 1 & 2
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Antenna Concepts
Gain
The amount of increase in energy that an antenna appears to
add to an RF signal
Measured in dBi (gain over theoretical isotropic)
More gain means focusing in certain directions, limited range of
coverage
Directionality
The coverage around the antenna
Omnidirectional antennas (360 degree coverage)
Directional antennas (limited range of coverage)
Polarization
The physical orientation of the element on the antenna that
emits the RF energy
Must match for a link to work properly
BCMSN 6 – 1 & 2
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Antenna Theory
A theoretical isotropic
antenna has a perfect
360 degree vertical and
horizontal beamwidth.
Reference for all
antennas.
BCMSN 6 – 1 & 2
119
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Omnidirectional Antenna: Dipole
Energy lobes “pushed in” from the
top and bottom
Higher gain
Smaller vertical
beamwidth
Side View
(Vertical Pattern)
Vertical Beamwidth
New Pattern (with Gain)
Larger horizontal lobe
Typical dipole pattern
Top View
(Horizontal Pattern)
2-dBi Dipole
"Standard Rubber
Duck"
BCMSN 6 – 1 & 2
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Directional Antenna
Lobes are pushed in a certain
direction, causing the energy to be
condensed in a particular area.
Very little energy is in the back side
of a directional antenna.
Side View
(Vertical Pattern)
Top View
(Horizontal Pattern)
6.5-dBi Diversity
Patch Wall Mount
– 55 degrees
BCMSN 6 – 1 & 2
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Connectorized 5-GHz Antennas
Cisco 5-GHz
Rubber Antenna
(Flat with Blue Dot)
Cisco 2.4-GHz
Rubber Antenna
(Round no dot)
5-GHz (802.11a) antennas
have blue ID markers.
Dual-band (2.4-GHz and 5-GHz)
antennas have yellow dots.
BCMSN 6 – 1 & 2
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Multipath Distortion
Multipath distortion (a form of radio degradation) occurs when radio
signals bounce off metal objects in a room, such as metal cabinets or
ceiling lights.
Multiple signals at receiver cause distortion of the signal.
As radio waves bounce, they arrive at the receiver slightly delayed,
combining with the original signal, causing distortion.
Diversity systems use two antennas in different positions to reduce the
degradation.
BCMSN 6 – 1 & 2
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Effective Isotropic Radiated Power (EIRP)
Transmit power is rated in dBm or mW.
Power coming off an antenna is Effective Isotropic Radiated
Power (EIRP).
EIRP is the power that the transmitter appears to have if it were
an isotropic radiator
FCC and ETSI use EIRP for power limits in regulations for 2.4GHz and 5-GHz WLANs.
BCMSN 6 – 1 & 2
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Autonomous
Access Point
Configuration
BCMSN 6 – 1 & 2
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Autonomous AP Configuration
Configuration
Web browser (preferred)
Cisco IOS command line
Serial console
Telnet or SSH
CiscoWorks WLSE (optional)
IP address required except for serial console
Set IP address on AP via DHCP or serial console
Find IP address of AP
BCMSN 6 – 1 & 2
DHCP server
CDP (switch)
Serial console
Other access point
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Role of Autonomous AP in Radio
Network
Cisco Aironet 1100, 1200, and 1300 Series
Access Point (Fallback to Radio Island)
Access Point (Fallback to Radio Shutdown)
Access Point (Fallback to Repeater)
Repeater (Non-Root access point)
Root Bridge
Non-Root Bridge
Root Bridge with Wireless Clients
Non-Root Bridge with Wireless Clients
Workgroup Bridge
Scanner
Bridge modes not supported on the Cisco 1100 Series
BCMSN 6 – 1 & 2
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Autonomous Access Point Homepage
BCMSN 6 – 1 & 2
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Express Setup
Initial configuration of access point: hostname, IP address, SNMP
BCMSN 6 – 1 & 2
129
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Lightweight Access
Point Configuration
BCMSN 6 – 1 & 2
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Getting started…
The bulk of the configuration tasks required to setup a
Centralized WLAN solution are performed on the
Wireless LAN Controller.
Lightweight Access Points are designed to be “zero
touch” and are not directly configured by the
administrator.
The very basic configuration tasks required on the WLC
are done via CLI, while more complex tasks are
completed after the web interface is accessible.
BCMSN 6 – 1 & 2
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WLC and Lightweight AP Configuration
These are the basic steps to getting the controller and
APs online:
Have a DHCP server present so that the APs can
acquire a network address.
Note: Option 43 is used if the APs reside in a different subnet.
Configure the WLC for basic operation.
Configure the switch for the WLC.
Configure the switch for the APs.
Register the lightweight APs to the WLCs.
BCMSN 6 – 1 & 2
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Lightweight WLAN Controller
Configuration
Initial setup
Command line via serial console
Ongoing configuration*
Web browser
Command line via serial console, Telnet,
or SSH
Cisco WCS (optional)
DHCP server for APs required
*Requires IP address to be configured on controller
BCMSN 6 – 1 & 2
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WLAN Controller Boot Menu
Cisco Bootloader (Version 3.2.78.0)
.o88b. d888888b .d8888.
d8P Y8
`88'
88' YP
8P
88
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8b
88
`Y8b.
Y8b d8
.88.
db
8D
`Y88P' Y888888P `8888Y'
.o88b.
d8P Y8
8P
8b
Y8b d8
`Y88P'
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.8P Y8.
88
88
88
88
`8b d8'
`Y88P'
Model WLC2006
Booting Primary Image...
Press <ESC> now for additional boot options...
Boot Options
Please choose an option from below:
1.
2.
3.
4.
5.
Run primary image (Version 3.2.78.0) (active)
Run backup image (Version 3.1.105.0)
Manually upgrade primary image
Change active boot image
Clear Configuration
Please enter your choice:_
BCMSN 6 – 1 & 2
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CLI Wizard Configuration Tool
BCMSN 6 – 1 & 2
135
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WLC Web User
Interface
BCMSN 6 – 1 & 2
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WLAN Controller Web Login
https://<ip-addr>
Default IP: 192.168.1.1/24
admin/admin
BCMSN 6 – 1 & 2
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WLAN Controller Web Menu Bar
WLANs
Provides WLAN
configurations
such as SSIDs
and security
policies for all
user groups
MONITOR
Provides a view
of this controller,
its access points,
and wireless
clients
BCMSN 6 – 1 & 2
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WIRELESS
Provides access
point
configurations,
clients
management,
and various RF
settings
CONTROLLER
Provides controllerwide configurations
such as Layer 2/3
mode, Multicast,
and mobility
settings
MANAGEMENT
Provides
integration into
the network such
as IP addressing
and SNMP
SECURITY
Provides
integration into
security structure
such as RADIUS
connectivity
COMMANDS
Provides
administrative
options such as
upgrades and
backups
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Monitor > Summary
BCMSN 6 – 1 & 2
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BCMSN 6 – 1 & 2
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