Components Review. CWNA Guide to Wireless LANs, Second Edition2 WLAN Devices In-building Infrastructure 1200 Series (802.11a and 802.11b) 1100 Series

Components Review

CWNA Guide to Wireless LANs, Second Edition 2

WLAN DevicesIn-building Infrastructure

• 1200 Series (802.11a and 802.11b)

• 1100 Series (802.11b)

• 350 Series (802.11b) not shown

Bridging

• 350 Series (802.11b)

•BR350

•WGB350

• 1400 Series (802.11a)


AntennasAntenna

•2.4GHz Antennas

•5 GHz Antennas


Cable, Accessories, Wireless IP PhoneCable and Accessories

• Low Loss Cable

• Antenna Mounts

• Lightening Arrestor

• Wireless IP Phone


Client AdaptersClients (NICs)

• 350 Series (802.11b)

• 5 GHz client adapter (802.11a)

Drivers are supported for all popular operating systems, including Windows 95, 98, NT 4.0, Windows 2000, Windows ME, Windows XP, Mac OS Version 9.x, and Linux.


Cisco Aironet 350 Series Mini PCI Adapter

• 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 1100 Series Access Point

• Aironet 1100 supports 802.11b

• 802.11b is upgradeable to 802.11g with a mini-PCI replacement.


1200 Series Access Point

• An access point (AP) acts as the center point of a stand-alone wireless network or as the connection point between wireless and wired networks.

• May provide roaming functionality with multiple APs.

• Aironet 1200 is a dual-band AP that supports both 802.11b and 802.11a.

• 802.11b is upgradeable to 802.11g with a mini-PCI replacement.


Cisco Aironet WLAN Solutions for the Enterprise

Cisco Aironet 1100 Series Cisco Aironet 1200 Series Intelligent Enterprise Services at a Lower Total Cost

Outstanding Enterprise Performance and Greatest Flexibility

Single 802.11b radio (upgradable to 802.11g with Advanced Encryption Standard (AES))

Dual-mode 802.11a and 802.11b support (upgradable to 802.11g with Advanced Encryption Standard (AES))

Integrated diversity dipole antennas for simplified deployment

Two 2.4 GHz antenna connectors for high gain diversity antennas; integrated 5 GHz antennas

Indoor environmental specifications, durable plastic case

Industrial environmental specifications, rugged metal case

Extra memory and system capacity for future releases

Extra memory and system capacity for future releases

Inline and Local Power Inline and Local Power

Cisco IOS-based operating system

Cisco IOS operating system

QOS, VLANs, and Proxy Mobile IP QOS, VLANs, and Proxy Mobile IP


Bridges – BR350

• BR350 is designed to connect two or more networks, typically located in different buildings.

• The BR350 wireless bridges provide up to 11 Mbps speed.

• The bridge is ideal for indoor or outdoor installations subject to plenum rating and harsh environments.


Bridges – WGB350

• Cisco Aironet 350 Series Workgroup Bridge (WGB350) quickly connects up to eight Ethernet-enabled laptops or other portable computers to a wireless WLAN, providing an 11 Mbps link from these devices to any Cisco Aironet 802.11b AP or Wireless Bridge.

• This bridge is for indoor use only.


Bridges – 1400

• Cisco Aironet 1400 Series Bridge operates at speeds up to 54 Mbps.

• High-performance 801.11a wireless bridge designed to connect multiple LANs in a metro area.

• The 1400 can only operate outdoors in a fixed point-to-point or point-to-multipoint application.


Cisco Aironet Wireless Bridging Solutions

Cisco Aironet 350 Series Cisco Aironet 1400 Series

Wireless Bridging at a Lower Total Cost

Wireless Bridging with high performance

Single 802.11b radio with data rates up to 11 Mbps

Single 802.11a radio with data rates up to 54 Mbps

3 miles typical point to point range with directional antennas at 11 Mbps

7.5 miles typical point to point range with directional antennas at 54 Mbps

Two 2.4 GHz antenna connectors for high gain diversity antennas

Single 5.8 GHz integrated patch array antenna or antenna connector for remote antennas

Indoor industrial environmental specifications, rugged metal case

Outdoor environmental specifications, tested to NEMA 4

Inline and Local Power Inline Power via Power Injector LR

VxWorks based operating system Cisco IOS operating system

QOS, VLANs, and Proxy Mobile IP QOS, VLANs, and Proxy Mobile IP

Statistics via telnet Antenna Alignment feedback via LEDs and RSSI port and statistics via telnet


Antennas• A variety of optional 2.4 GHz

and 5 GHz antennas are available for Cisco wireless devices. Antennas should be chosen carefully to ensure that optimum range and coverage is obtained

• Coupling the right antenna with the right AP allows for efficient coverage in any facility, as well as better reliability at higher data rates.

• A detailed coverage of antennas will be provided later in the course.


Antennas

• 2.4 GHz • 5 GHz

• Indoor and Outdoor• WLAN and Bridging

• Outdoor• Bridging


Beyond Laptops:Other 802.11-Enabled Devices

• PDA’s

• Phones

• Printers

• Projectors

• Tablet PC’s

• Security Cameras

• Barcode scanners

• Custom devices for vertical markets:

–Healthcare–Manufacturing–Retail–Restaurants

HP iPAQ 5450 PDA

Compaq Tablet PC

HHP Barcode Scanner

Epson Printer

Sharp M25X Projector

SpectraLink Phone

CWNA Guide to Wireless LANs, Second Edition

“Business-Class”vs Consumer WLAN

• Industry has segmented: consumer vs. business

• “Cisco” offers only “business-class” products:

–Security–Upgradeability–Network management–Advanced features–Choice of antennas–Highest throughput–Scalability


Consumer wireless products

• There is a real difference in functionality and administrative capabilities between Business-class and Consumer wireless products.


Wireless LAN Topologies


Wireless LAN Topologies

• Without a wireless alternative, organizations frequently resort to wide area networking (WAN) technologies to link together separate facilities.

• Contracting for leased-line or other wide-area services often presents a variety of drawbacks:

• Installation is typically expensive and rarely immediate

• Monthly fees are often quite high for bandwidth

• A wireless bridge can typically be purchased and installed in a day with no recurring charges.

Wireless LAN Market


Implications

• Over the last decade, the networking and wireless communities expected each year to become the year of the WLAN.

• WLAN technology had some false starts in the 1990s, for a variety of reasons. Immature technology, security concerns, and slow connectivity speeds kept WLAN technology from becoming a viable alternative to wired LANs.


WLAN growth and applications

Don’t know the source of this and there is considerable debate whether 802.11a will win out over 802.11b/g


Momentum is Building in Wireless LANs

• Wireless LANs are an “addictive” technology

• Strong commitment to Wireless LANs by technology heavy-weights–Cisco, IBM, Intel, Microsoft

• Embedded market is growing–Laptop PC’s with “wireless inside”–PDA’s are next

• The WLAN market is expanding from Industry-Specific Applications, to Universities, Homes, & Offices

• Professional installers and technicians will be in demand


Wireless LANs Are Taking Off

($ Billions)

Source: Forward Concepts, 2003

Future Growth Due To:

StandardsHigh Bandwidth NeedsLow CostEmbedded in LaptopsVariety of DevicesVoice + DataMultiple ApplicationsSecurity Issues SolvedEase of DeploymentNetwork Mgmt. ToolsEnterprise Adoption

Worldwide WLAN Market*includes embedded clients, add-on client cards, & infrastructure equipment for both the business and consumer segments

CAGR = 43%


Four main requirements for a WLAN solution 1. High availability — High availability is achieved through system

redundancy and proper coverage-area design. 2. Scalability — Scalability is accomplished by supporting multiple

APs per coverage area, which use multiple frequencies. APs can also perform load balancing, if desired.

3. Manageability — Diagnostic tools represent a large portion of management within WLANs. Customers should be able to manage WLAN devices through industry standard APIs, including SNMP and Web, or through major enterprise management applications like CiscoWorks 2000, Cisco Stack Manager, and Cisco Resource Monitor.

4. Open architecture — Openness is achieved through adherence to standards such as 802.11a and 802.11b, participation in interoperability associations such as the Wi-Fi Alliance, and certification such as U.S. FCC certification.


Other requirements

• Security — It is essential to encrypt data packets transmitted through the air. For larger installations, centralized user authentication and centralized management of encryption keys are also required.

• Cost — Customers expect continued reductions in price of 15 to 30 percent each year, and increases in performance and security. Customers are concerned not only with purchase price but also with total cost of ownership (TCO), including costs for installation.

Challenges and Issues


Radio Signal Interference

• Network managers must ensure that different channels are utilized.

• Interference cannot always be detected until the link is actually implemented.

• Because the 802.11 standards use unlicensed spectrum, changing channels is the best way to avoid interference.

• If someone installs a link that interferes with a wireless link, the interference is probably mutual.


Radio Signal Interference

• Many other devices such as portable phones, microwave ovens, wireless speakers, and security devices, also use these frequencies.

• It is possible for electromagnetic interference (EMI) to be generated by non-radio equipment operating in close proximity to the Cisco Aironet WLAN equipment.

• While it is theoretically possible for this interference to directly affect the reception and transmission of signals, it is more likely to affect the components of the transmitter.

• To minimize the possible effects of EMI, the best course of action is to isolate the radio equipment from potential sources of EMI.


Power Consumption

• Power consumption is always an issue with laptops, because the power and the battery have limited lives.

• 802.11a uses a higher frequency (5 GHz) than 802.11a/g (2.4 GHz) which requires higher power and more of a drain on batteries.


Interoperability

• Non-standard (for now) 802.11 devices include:

• Repeater APs

• Universal Clients (Workgroup Bridges)

• Wireless Bridges

• Cisco bridges, like many other vendor bridges, are proprietary implementations of the 802.11 standard and therefore vendor interoperability cannot be attained.


Wireless LAN Security: Lessons

“War Driving”

Hacking into WEP

Lessons:

• Security must be turned on (part of the installation process)

• Employees will install WLAN equipment on their own (compromises security of your entire network)

• WEP keys can be easily broken (businesses need better security)


Wireless LAN Security

• Security in the IEEE 802.11 specification—which applies to 802.11b, 802.11a, and 802.11g—has come under intense scrutiny.

• Researchers have exposed several vulnerabilities.

• As wireless networks grow, the threat of intruders from the inside and outside is great.

• Attackers called “war drivers” are continually driving around searching for insecure WLANs to exploit.


Wireless LAN Security

• The IEEE enhanced Wired Equivalent Privacy (WEP) with Temporal Key Integrity Protocol (TKIP) which provides robust authentication options with 802.1x to make 802.11-based wireless LANs secure.

• We will also look at WPA (WiFi Protected Access, TKIP + MIC)• At the same time, the IEEE is looking for stronger encryption

mechanisms. • The IEEE has adopted the use of the Advanced Encryption

Standard (AES) to the data-privacy section of the proposed 802.11i standard.


Reliability and Connectivity

• Wireless LANs include mechanisms to improve the reliability of the packet transmissions to be at least the same level as wired Ethernet.

• Using the TCP/IP protocols will help protect the network against any loss or corruption of data over the air.

• Most WLAN systems use spread-spectrum technology or orthogonal frequency-division multiplexing (OFDM).We will look at these in much more detail later.

• Too much to go into right now.


Installation and Site Design Issues—Bridging


Installation and Site Design Issues—WLAN


Health Issues


IEEE 802.11 Standards Activities• 802.11a: 5GHz, 54Mbps

• 802.11b: 2.4GHz, 11Mbps

• 802.11d: Multiple regulatory domains

• 802.11e: Quality of Service (QoS)

• 802.11f: Inter-Access Point Protocol (IAPP)

• 802.11g: 2.4GHz, 54Mbps

• 802.11h: Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC)

• 802.11i: Security

• 802.11j: Japan 5GHz Channels (4.9-5.1 GHz)

• 802.11k: Measurement

Documents

Components Review. CWNA Guide to Wireless LANs, Second Edition2 WLAN Devices In-building Infrastructure 1200 Series (802.11a and 802.11b) 1100 Series