Introduction to Wireless Networking Module-2 Wireless Local Area Networking Clients and WLAN Devices
CCRI ENGINEERING AND TECHNOLOGY Jerry Bernardini
CCRI Engineering and Technology Jbernardini
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REFERENCES CWTS Chapter-3
CCRI Engineering and Technology
Jbernardini
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WLAN Client Devices • PC Cards – – – –
ExpressCard CardBus PCMCIA Some support external antennas
• USB devices – External cable – Variable position and antenna
• • • •
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 – – – –
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. 2/8/2012
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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.. 2/8/2012
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Thin Access Points Implementation
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Access Points Market
Belkin APs
Buffalo APs
Cisco APs 2/8/2012
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 2/8/2012
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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
3
Switch
CAT-5e Ethernet
DC Power
AC Power DC Power
PSE Injector
CAT-5e Ethernet
Tap/Splitter
Access Point
Wireless Bridges • • • •
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. – – – –
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 – – – –
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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