Transcript 1 2 3 - Community College of Rhode Island

Wireless Networking
Wireless Devices
Module-7A
Jerry Bernardini
Community College of Rhode Island
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Presentation Reference Material
• CWNA Certified Wireless Network
Administration Official Study Guide
(PWO-104), David Coleman, David Westcott,
2009, Chapter-10
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WLAN Client Devices
• PC Cards
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ExpressCard
CardBus
PCMCIA
Some support external antennas
• USB devices
– External cable
– Variable position and antenna
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Compact Flash Devices
SD Devices
PCI Cards
Mini-PCI Cards
– Laptop applications
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Cisco Aironet 802.11b Client Adapters
• 2.4 GHz
– 802.11b
– 11 Mbps
• Include
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PC Card
PCI Card
LMC Card
Mini PCI
Cisco Aironet 350 Series Mini PCI
• 2.4 GHz/802.11b
embedded wireless for
notebooks
• 100 mW transmit power
• Must order through PC
manufactures (not
orderable directly
through Cisco)
Cisco Aironet 802.11a Client Adapter
•5 GHz/802.11a
– 54 Mbps
•Rate Shifting
– 6, 9, 12, 18, 24, 36, 48, or 54
•Fixed data rates
– User configurable option
•5 dBi Patch Antenna
•CardBus interface
•Transmit power settings:
– 20 mW, 10 mW, and 5 mW
PCMCIA, (PC) Cards
Compact Flash
• Compact Flash, (CF) - CompactFlash Association,
CFA
CF Wireless 802.11b (WiFi)
Wireless USB Adapters
PCI and ISA Adapters
Adapters
SD to USB
SD to PC
CF to
PC
USB to Serial
Ethernet Adapters
Access Points
• The Access Point (AP) is the device that provides access to
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the WLAN
Each BSS has one AP and multiple Aps make an ESS
Two categories of APs are Fat and Thin Access Points
Thin AP’s are paired with a wireless LAN switch or controller
to offer additional functionality and centralization over Fat
AP’s.
Fat (Thick or Smart) AP’s are "fat" because they operate
autonomously as members of a decentralized WLAN.
3Com Wireless LAN Switch WX1200
3Com AP3750 MAP
Autonomous or FAT Access Points
• Traditional wireless LANs use decentralized Fat
access points
• Manual configuration required to set the power
level, channel, security and other configurable
parameters.
• Each access point is individually configured
• Third party software solutions are often needed for
additional security and management capabilities
• For large networks which quickly add to the total
cost of ownership.
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Autonomous AP Implementation
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Lightweight or Thin Access Points
• Centralized WLANs use a wireless controller to
manage, process, and configure the RF environment
• Centralized WLANs use called thin or lightweight APs
• Aps communicate directly with the central controller
with the wired network
• All the functionality and intelligence is offloaded to
the controller
• This provides a single point of administration for
various policies relating to security, intrusion
detection, user roles, and software upgrades..
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Thin Access Points Implementation
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Access Points Market
Belkin APs
Buffalo APs
Cisco APs
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Linksys APs
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Access Point Features
• Support of various IEEE 802.11 standards
– FHSS, DSSS, OFDM, 802.11a,b, g, n
• Support for various security standards
– IEEE 802.11i, WEP, WPA, WPA2, PSK, RADIUS
• Support for QoS extensions
– Wireless Multimedia (WMM), VoWLAN
• Fixed or Detachable Antenna
– Omni-directional, Directional
• Filtering
– MAC, Protocol
• Variable Power
– Percent of Max or Actual Levels
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Power Over Ethernet (PoE) Support
• Found on Enterprise and not on SOHO APs
• Primary benefit is ability to install APs where no AC
power is present
• IEEE 802.3af standard for PoE
• PoE is supply by injectors or switches
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PoE Options and Power Source Equipment(PSE)
Pins 4-5 +Power(48v)
Pins 7-8 –Power
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Active/PSE
Switch
PD Access Point
DC Power
CAT-5e Ethernet
PD Access Point
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Switch
AC Power
DC Power
PSE Injector
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Switch
CAT-5e Ethernet
DC
Power
AC Power
DC Power
PSE Injector
CAT-5e Ethernet
Tap/Splitter
Access Point
Wireless Bridges
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Provides a link between two WLAN segments
Not full described by IEEE 802.11
Vendor dependent
Two Modes – Root and Non-root
Non-Root
Point-to-Point
Non-Root
Root
Non-Root
Point-to-Mulitpoint
Root
WLAN Bridge Modes and Components
• Root Mode – A bridge that acts as the hub to a group of
bridges.
– Only One Root-Bridge for PtP or PtMP links (important for tests)
– For PtP link one Root-Bridge and one Non-Root Bridge
• Non-Root Mode – A member bridge of a group that is not the
Root Bridge.
– Can also function as a standard AP
– Can function as a repeater
3Com WLAN Bridge
Cisco Aironet 1400
Proxim Quick Bridge 11
Bridge Application: School District
Richardson
Elementary
Yagi
Bode
Elementary
Yagi
Roberts
Middle School
Dish
High School 2
Bridges
One 12 dBi omni
One Dish
Channel #1
Channel #6
Channel #11
Price
Elementary
Yagi
WeaverSpecial
Education
Dish
UNIVERSITY
Administration
2 Bridges
One 12 dBi omni
One Yagi
Lincoln
Elementary
Yagi
Bolich
Dewitt Elementary Middle
School
Yagi
Yagi
Residential WLAN Gateways
• Same as SOHO wireless routers
• Support of various IEEE 802.11 standards
– FHSS, DSSS, OFDM, 802.11a,b, g, n
• Support for various security standards
– IEEE 802.11i, WEP, WPA, WPA2, PSK, RADIUS
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Built in firewall features
Packet and MAC Filtering
Switched Ethernet ports
DHCP
NAT and PAT
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Enterprise WLAN
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Enterprise Wireless Gateways
• Enterprise Wireless Gateway – is a powerful device that
interfaces between the enterprise network and the corporate
firewall.
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HTML  WML
Authentication, Filtering, and Security
Traffic Management, QoS
Mobile Addressing
Vernier IS 6500p
BlueSecure Controller
BSC 2100
Enterprise Wireless Gateways
Internet
Enterprise
Server
Enterprise
Gateway
Router
Switch
Access
Points
Wireless
Clients
Wireless Mesh Access Points
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Mesh APs associate with multiple APs
Association between APs is limited by vendor (3-5)
Currently vendor dependent
Clients can reach destinations thru multiple APs
APs route packets to ovoid failures and optimal paths
Mesh Networks are more resilient
Not every AP has to be connected to a wired network
Self-Healing, Self-Configuring using Layer-2 Protocol
New standard IEEE 802.11s will allow interoperability
between vendors
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Wireless Mesh Network Implementation
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Voice Over IP WLAN (VoWLAN)
• Telephone communication using a WLAN requires latency and
QoS considerations
• Special equipment is required
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VoWLAN phone (phones that will connect to WLAN)
WLAN infrastructure with QoS (low latency and Protocol management)
Call management (PBX for IP phones)
Voice gateway for outside calls
• IP phones associate with APs rather than cellular towers
Siemens Linksys
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