Ch. 6 - Bridgesleaman.org/wireless/mod6-Bridges.pdfRick Graziani [email protected] 2 •...

Ch. 6 - Bridges

Cisco Fundamentals of Wireless LANs version 1.1Cisco Fundamentals of Wireless LANs version 1.1

Rick Graziani

Cabrillo College

Overview

Rick Graziani [email protected] 2

• Designed to connect two or more networks, typically located in different buildings, wireless bridges deliver high data rates and superior throughput for data-intensive, line-of-sight applications.

• The bridges connect hard-to-wire sites, noncontiguous floors, satellite offices, school or corporate campus settings, temporary networks, and warehouses.

• The high-speed links between the wireless bridges deliver throughput many times faster than E1/T1 lines for a fraction of the cost, thus eliminating the need for expensive leased lines or difficult-to-install fiber-optic cable.

802.11a

Bridge Connection

Bridging Defined

• Bridges are used

to connect two or

more wired LAN’s,


more wired LAN’s,

usually located

within separate

buildings, to create

one large LAN.

Technology Comparisons

TechnologyTechnology Installation Cost

Installation Cost

Monthly Cost (USD)

Monthly Cost (USD)

Dialup or 56K

Dialup or 56K

$25 to $50$25 to $50$0 to $250$0 to $250

Barriers to ImplementBarriers to Implement

Remote locationsRemote

locations

Cable/DSLCable/DSL $0 to $250+$0 to $250+ $25 to $150$25 to $150 ReliabilityReliability

Rick Graziani [email protected]

Recurring CostRecurring CostE1, T1E1, T1

FiberFiberPhysical

obstructionsPhysical

obstructions

$250 to $1,000+$250 to $1,000+ $400 to $1000+$400 to $1000+ AvailabilityAvailability

$5,000 to $200,000+$5,000 to $200,000+ $0$0

MicrowaveMicrowave Licensing, Weather

Licensing, Weather

$15,000+$15,000+ $0$0

802.11802.11 $2,000 to $15,000

$2,000 to $15,000 $0$0 InterferenceInterference

Monthly Leased Line OpEx

2 DS1: $600

1 DS3: $5000

TOTAL: $5600

RBOC

DS3

DS1

DS1

Traditional WAN Connectivity


RBOC provides guaranteed level of service via a Service Level Agreement (SLA)

DS3

New remote office

- No DS1 connection available

Monthly Line Cost

2 DS1: $600

1 Fractional DS3: $3000

TOTAL: $3600

RBOC

2 Mbps

802.11b Connectivity


Wireless Installation Cost

7 350 Series Bridges Installed: $12,500 USD

Pay Back Period: 3 months

New building connected

Self managed

22 Mbps

2 Mbps

5 Mbps

Monthly Line Cost

2 DS1: $600

1 DS3: $5000

TOTAL: $5600

RBOC

14 Mbps

802.11a Connectivity


Wireless Installation Cost

7 1400 Series Bridges Installed: $40,000 USD

Pay Back Period: 8 months

New building connected

Self managed

50 Mbps

14 Mbps

27 Mbps

Role in Radio Network

• Role in Radio Network

– Determines functionality within WLAN

– Determines which

File Server

BridgeBridgeWorkgroup

BridgeWorkgroup

Bridge

Bridge


– Determines which type of clients will be supported Access PointAccess Point

PC CardPC CardPCI CardPCI Card

Introduction


• The BR350 is sometimes called the multifunction bridge.

Bridges


• Cisco bridges can be controlled and configured though command line and Web interfaces.

• Management can also be done through traditional protocols like SNMP.

Bridge roles in the network


• The Cisco bridges can be configured to operate in different modes.

• The BR350, or multifunction bridge, has the same receiver sensitivity, power

levels, and capabilities, as the Cisco Aironet APs with .11b radio chips.

Parent-Child Relationship: Root - Non-Root



Root Access Point


• Root Access Point—Use this setting to set up the bridge as a rugged access point connected to the wired LAN. When you select Access Point, the bridge's Spanning Tree Protocol (STP) function is disabled.


Root Bridge


• Root bridge—One bridge in each group of bridges must be set as the root bridge. A root bridge can only communicate with non-root bridges and other client devices and cannot associate with another root bridge.



• Non-Root Bridge w/Clients—Use this setting for non-root bridges that will accept associations from client devices, and for bridges acting as repeaters. Non-root bridges can communicate with other non-root bridges, root bridges, and client devices.

Non-Root Bridge with Clients


Non-Root Bridge without Clients


• Non-Root Bridge w/o Clients—Use this setting for non-root bridges that should not accept associations from client devices. A bridge set to Non-Root Bridge w/o Clients will only communicate with a root or non-root bridge.


Repeater Access Point


• Repeater Access Point—Use this setting to set up the bridge as a rugged repeater access point. A repeater access point is not connected to the wired LAN; it is placed within radio range of an access point connected to the wired LAN to extend the range of your infrastructure or to overcome an obstacle that blocks radio communication. When you select Repeater Access Point, the bridge's STP function is disabled.

Power Options


Distances Limited by 802.11 Specification


BR350—Front Cover LED’s


802.11b Bridge

Bridge ModelBridge Model

BR350BR350

Data Rate Data Rate

11 Mbps11 Mbps

11 Mbps11 Mbps

20.5 33.0 20.5 33.0

32.7 52.532.7 52.5

21 dBi Dish21 dBi Dish

Max. Distance

Miles Km

Max. Distance

Miles Km

Optional Antenna Optional Antenna

Standard Cable (6.7 dB/100 ft. loss)

(6.7 dB/30.5 m)

Standard Cable (6.7 dB/100 ft. loss)

(6.7 dB/30.5 m)


50 ft (15.2m)/side50 ft (15.2m)/side

20 ft (6.1m)/side20 ft (6.1m)/side


BR350BR350

Note: Distances over 25 miles or 40 Km are very hard to align and install!

51.7 83.251.7 83.2

32.6 52.432.6 52.4

41.0 66.041.0 66.02 Mbps2 Mbps

5.5 Mbps5.5 Mbps

1 Mbps1 Mbps




50 ft (15.2m)/side50 ft (15.2m)/side

50 ft (15.2m)/side50 ft (15.2m)/side

50 ft (15.2m)/side50 ft (15.2m)/side

802.11b Common Questions

Cisco Aironet BridgeCisco Aironet Bridge How Fast?How Fast?

Max data rateMax data rate 11 Mbps11 Mbps

5.5 Mbps5.5 Mbps

How Far? How Far?

Typical throughputTypical throughput

2 Mbps2 Mbps

1.4 Mbps1.4 Mbps


20.5 Miles 33 Km20.5 Miles 33 Km

3.6 Miles 5.8 Km3.6 Miles 5.8 Km

How Far? How Far?

Yagi antennaYagi antenna 7.3 miles 11.7 Km7.3 miles 11.7 Km

25+ miles 40+ Km25+ miles 40+ Km

Dish antennaDish antenna

Note: All distances may be limited by governing bodies and standards.

Optional 2.4GHz Antennas for Long Range


• 13.5 dBi YagiDistances over

7.3 miles @ 2 Mbps11.7 Km @ 2 Mbps3.6 miles @ 11 Mbps5.8 Km @ 11 Mbps

• 21 dBi Solid DishFor distances up to

25+ miles @ 2 Mbps40+ Km @ 2 Mbps 20.5 miles @ 11 Mbps33 Km @ 11 Mbps

Note: Distances include 50 feet of low loss cable and 10 dB fade margin

802.11b Bridge Application: School District

RichardsonElementaryYagi

RobertsMiddle SchoolDish

Weaver-Special EducationDish


LincolnElementaryYagi

BodeElementaryYagi

PriceElementaryYagi

Dewitt ElementaryYagi

BolichMiddle SchoolYagi

High School 2 BridgesOne 12 dBi omniOne Dish Administration

2 BridgesOne 12 dBi omniOne Yagi

U N I V E R S I T YU N I V E R S I T Y

Channel #11

Channel #6

Channel #1

Lightning


Lightning Arrestor

• Designed to protect LAN

devices from static

electricity and lightning

To Antenna

Lug


electricity and lightning

surges that travel on coax

transmission lines

• RP-TNC connectors used

on all Cisco Antennas

Ground Wire

From RF Device

Lug

Lockwasher

Nut

Direct Strike Protection


Coax Connection Sealing

• Number one problems with

bridges - water in the

connectors

• Proper sealing

is important


is important

• Coax Seal is one product

that is inexpensive and

works great

Path Loss Considerations

The following are needed to determine coverage · Antenna Gain· Transmitter Power· Receiver Performance· Cable Losses· Environmental Structures


· Environmental Structures

Calculations of Coverage Performance

Coax Length100 ft (30.5 m)?

Towers needed to clear trees andother buildings


Coax Length150 ft (45.7)?

Wants 11 Mbps data rateDistance = 13 miles (20.9 Km)

LED indicators


• When the bridge is powering on, all three LEDs normally blink.

• After bootup, the colors of the LEDs represent the following:

– Green LEDs indicate normal activity.

– Amber LEDs indicate errors or warnings.

– Red LEDs mean the unit is not operating correctly or is being upgraded.

Connecting to the Bridge


• There are 3 basic GUI interfaces depending on the bridge image:

– IOS 1400

– VxWorks BR350

– SOS WGB350

1400 with IOS GUI


BR350 with VxWorks GUI


WGB350 with SOS GUI ad SOS Menu


Resetting the Bridge

• Resetting the Cisco bridges depends on the model.

• The BR350, can be reset via the console, telnet, or browser


• The BR350, can be reset via the console, telnet, or browser connection.

– If the password is unknown, then the console reset method is required.

– The console port on the BR350.

– The :resetall command can be used after rebooting the bridge, however the command must be entered within 2 minutes of rebooting.

• The 350 Series Workgroup Bridge or the 1400 series bridge can be reset to default values via the Reset button, telnet, or browser connection.

Default Settings for BR350 and 1400


Default Settings for WGB 350


Basic Configuration

Will will not use or discuss all of the configuration Will will not use or discuss all of the configuration

options and features.

BR350 Home Page (Summary Status)


BR350 Map Link


• The Map link opens the Map window, which contains links to every management page.

• The Map window can be used to jump quickly to any system management page, or to a map of the entire wireless network

BR350 Network Link


BR350 Associations Link


BR350 Setup Link


• The Setup link displays the Setup page, which contains links to the management pages with configuration settings.

BR350 Logs Link


BR350 - Basic Configuration


• Connect just like an AP, suggest wired GUI.

• Remember to set the IP address on your Ethernet NIC.

Root Bridge and Non-Root Bridges


Non-Root Bridge without ClientsRepeater Bridge


Bridge as Root Access Point


Bridge as Repeater Access Point


Root Radio Identification configuration


• The current IP subnet mask displayed under the setting shows the IP subnet mask currently assigned to the bridge. This is the same subnet mask as the default subnet mask unless DHCP or BOOTP is enabled. If DHCP or BOOTP is enabled, this is the subnet mask used by the DHCP or BOOTP server.

• You can also enter this setting on the Express Setup page.

Root Radio Identification Page

• Primary Port Settings: Two options allow for the designation of the radio port as the primary port on the bridge:

• Primary Port? The primary port determines the MAC and IP addresses of the bridge.

– The default primary port of the bridge is the Ethernet port.

– The Ethernet port is connected to the wired LAN, so this setting is


– The Ethernet port is connected to the wired LAN, so this setting is usually set to no.

– Select no to set the Ethernet port as the primary port.

– Select yes to set the radio port as the primary port.

• Adopt Primary Port Identity?

– Select yes, to adopt the primary port MAC and IP addresses for the radio port.

– Select no to use different MAC and IP addresses for the radio port. Bridges acting as root units adopt the primary port settings for the radio port.

• When putting a bridge in standby mode, select no for this setting.

Root Radio Hardware configuration


• Similar to an AP.

Root Radio Hardware configuration


Ethernet Identification configuration


• Addressing is similar to Root Radio options

Ethernet Hardware configuration


Configuring time services


Configuring boot services


Configuring name services


Configuring routing services


Configuring routing services


• Manage Installation Keys is used to read specifications of the software license and to install a new license.

• Manage System Configuration is used to restart the device, download a configuration file, or reset settings to factory defaults.

• Distribute Configuration to other Cisco Devices is used to send the configuration of the device to other Cisco Aironet devices on the network.

• Distribute Firmware to other Cisco Devices is used to send a new firmware version to other Cisco Aironet devices on the network.

CDP


Distribute Firmware to Other Cisco Devices


Hot Standby Management


1400 Series Bridge

801.11a wireless bridge801.11a wireless bridge

Overview


• The Cisco Aironet 1400 Series Wireless Bridge is a high-performance 801.11a wireless bridge designed to connect multiple LANs in a metropolitan area.

• Designed to be a cost-effective alternative to leased lines, it is engineered specifically for harsh outdoor environments . The features of the 1400 include:

Overview


• Support for both point-to-point or point-to-multipoint configurations

• Support data rates up to 54 Mbps

• Enhanced security mechanisms based on 802.11i standards

• Rugged enclosure optimized for harsh outdoor environments with extended operating temperature range

• Integrated or optional external antennas for flexibility in deployment

Overview


• Data rates of 54 Mbps can be enabled for point-to-point links up to 7.5 miles, and for point-to-multipoint links up to 2 miles.

• Aggregate throughput can be obtained in excess of 28 Mbps.

• Also, by using higher gain antennas or lower data rates, ranges in excess of 20 miles point-to-point can be covered.

Models and options


• There are two options for ordering the Cisco Aironet 1400 Series Wireless Bridge:

– Cisco Aironet 1410 Wireless Bridge with 22.5 dBi Antenna, FCC Config

– Cisco Aironet 1410 Wireless Bridge with N-Type Connector, FCC Config

Models and options


Components and accessories


Cisco Aironet Power Injector

Mounting Kit

IOS features


802.11a Bridge

Bridge ModelBridge Model

14001400

Data Rate Data Rate

54 Mbps54 Mbps

9 Mbps9 Mbps

12 xx.0 12 xx.0

23 xx23 xx


Max. Distance

Miles Km

Max. Distance

Miles Km

Optional Antenna Optional Antenna



14001400

Note: Distances over 25 miles or 40 Km are very hard to align and install!

7.5 xx7.5 xx

9 xx9 xx16 Mbps16 Mbps

54 Mbps54 Mbps 22 dBi Int.22 dBi Int.

22 dBi Int.22 dBi Int.

Optional 5GHz Antennas for Long Range

• Network configurations

–Point to point

–Point to multi-point

• Roof, pole, and wall mounting options

• 9.5 dBi sector (H or V

polarization)


mounting options

• 5.8 GHz Unlicensed Band Operation

–Rapid deployment and re-commissioning

• Operating temp range: -30 to +55

oC

• Humidity: 0 to 100%

• 9 dBi omni (Vertical polarization)

• 28 dBi dish (H or V

polarization)

Bridge Range Calculation Utility


Bridge Distance Calculations (cont.)


Ch. 6 - Bridges

Cisco Fundamentals of Wireless LANs version 1.1Cisco Fundamentals of Wireless LANs version 1.1

Rick Graziani

Cabrillo College

Ch. 6 - Bridgesleaman.org/wireless/mod6-Bridges.pdfRick Graziani [email protected] 2 •...

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Transcript of Ch. 6 - Bridgesleaman.org/wireless/mod6-Bridges.pdfRick Graziani [email protected] 2 •...