Ch. 6 - Bridges
Overview 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 a
Bridge Connection
Bridging Defined Bridges are used to connect two or more wired LAN’s, usually located within separate buildings, to create one large LAN.
Technology Comparisons Technology Recurring Cost Installation Cost Monthly Cost (USD) Dialup or 56K $25 to $50 $0 to $250 Barriers to Implement Remote locations Cable/DSL $0 to $250+ $25 to $150 E1, T1 Reliability Fiber Physical obstructions $250 to $1,000+ $400 to $1000+ Availability $5,000 to $200,000+ $0 Microwave Licensing, Weather $15,000+ $ $2,000 to $15,000 $0 Interference
Monthly Leased Line OpEx 2 DS1: $600 1 DS3: $5000 TOTAL: $5600 RBOC provides guaranteed level of service via a Service Level Agreement (SLA) RBOC DS3 DS1 New remote office - No DS1 connection available Traditional WAN Connectivity
Monthly Line Cost 2 DS1: $600 1 Fractional DS3: $3000 TOTAL: $3600 Wireless Installation Cost Series Bridges Installed: $12,500 USD Pay Back Period: 3 months New building connected Self managed RBOC 22 Mbps 2 Mbps 5 Mbps b Connectivity
Monthly Line Cost 2 DS1: $600 1 DS3: $5000 TOTAL: $5600 Wireless Installation Cost Series Bridges Installed: $40,000 USD Pay Back Period: 8 months New building connected Self managed RBOC 50 Mbps 14 Mbps 27 Mbps a Connectivity
Role in Radio Network –Determines functionality within WLAN –Determines which type of clients will be supported File Server Bridge Access Point PC Card PCI Card Workgroup Bridge Bridge
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
Bridge roles in the network 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 Access Point
Bridge roles in the network 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. Root Bridge
Bridge roles in the network 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
Bridge roles in the network 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. Non-Root Bridge without Clients
Bridge roles in the network 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. Repeater Access Point
Power Options
Distances Limited by Specification
BR350—Front Cover LED’s
802.11b Bridge Bridge Model BR350 Note: Distances over 25 miles or 40 Km are very hard to align and install! Data Rate 11 Mbps dBi Dish Mbps 5.5 Mbps Max. Distance Miles Km Max. Distance Miles Km 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) 1 Mbps 21 dBi Dish 50 ft (15.2m)/side 20 ft (6.1m)/side 50 ft (15.2m)/side
802.11b Common Questions Cisco Aironet Bridge How Fast? Max data rate 20.5 Miles 33 Km 11 Mbps 5.5 Mbps 3.6 Miles 5.8 Km How Far? Typical throughput Yagi antenna 2 Mbps 1.4 Mbps 7.3 miles 11.7 Km 25+ miles 40+ Km Dish antenna Note: All distances may be limited by governing bodies and standards.
Optional 2.4GHz Antennas for Long Range 13.5 dBi Yagi Distances over Mbps Mbps 21 dBi Solid Dish For distances up to Mbps Mbps Note: Distances include 50 feet of low loss cable and 10 dB fade margin
802.11b Bridge Application: School District Lincoln Elementary Yagi Bode Elementary Yagi Richardson Elementary Yagi Price Elementary Yagi Dewitt Elementary Yagi Bolich Middle School Yagi Roberts Middle School Dish Weaver- Special Education Dish High School 2 Bridges One 12 dBi omni One Dish Administration 2 Bridges One 12 dBi omni One Yagi Channel #11 Channel #6 Channel #1
Lightning
Lightning Arrestor Designed to protect LAN devices from static electricity and lightning surges that travel on coax transmission lines RP-TNC connectors used on all Cisco Antennas To Antenna 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 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
Calculations of Coverage Performance Coax Length 150 ft (45.7)? Coax Length 100 ft (30.5 m)? Wants 11 Mbps data rate Distance = 13 miles (20.9 Km) Towers needed to clear trees and other buildings
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 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.
Basic 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 Clients Repeater 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 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
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 a wireless bridge
Overview The Cisco Aironet 1400 Series Wireless Bridge is a high-performance a 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 i 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 Model 1400 Note: Distances over 25 miles or 40 Km are very hard to align and install! Data Rate 54 Mbps 9 Mbps 12 xx.0 23 xx 7.5 xx 28 dBi Dish 9 xx 16 Mbps 54 Mbps Max. Distance Miles Km Max. Distance Miles Km Optional Antenna 28 dBi Dish 22 dBi Int.
Optional 5GHz Antennas for Long Range Network configurations –Point to point –Point to multi-point Roof, pole, and wall mounting options 5.8 GHz Unlicensed Band Operation –Rapid deployment and re-commissioning Operating temp range: - 30 to +55 o C Humidity: 0 to 100% 9 dBi omni (Vertical polarization) 9.5 dBi sector (H or V polarization) 28 dBi dish (H or V polarization)
Bridge Range Calculation Utility
Bridge Distance Calculations (cont.)