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Ch. 6 - Bridges Overview 802.11a • 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. 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 Installation Cost Monthly Cost (USD) Barriers to Implement Dialup or 56K $0 to $250 $25 to $50 Remote locations Cable/DSL $0 to $250+ $25 to $150 Reliability E1, T1 $250 to $1,000+ $400 to $1000+ Recurring Cost Availability Fiber $5,000 to $200,000+ $0 Physical obstructions Microwave $15,000+ $0 Licensing, Weather $2,000 to $15,000 $0 Interference 802.11 Traditional WAN Connectivity Monthly Leased Line OpEx 2 DS1: RBOC DS1 $600 1 DS3: $5000 TOTAL: $5600 DS1 DS3 New remote office - No DS1 connection available RBOC provides guaranteed level of service via a Service Level Agreement (SLA) 802.11b Connectivity Monthly Line Cost 2 DS1: RBOC $600 1 Fractional DS3: $3000 2 Mbps TOTAL: $3600 2 Mbps 22 Mbps Wireless Installation Cost 7 350 Series Bridges Installed: $12,500 USD Pay Back Period: 3 months 5 Mbps New building connected Self managed 802.11a Connectivity Monthly Line Cost 2 DS1: RBOC $600 1 DS3: $5000 14 Mbps TOTAL: $5600 14 Mbps 50 Mbps Wireless Installation Cost 7 1400 Series Bridges Installed: $40,000 USD Pay Back Period: 8 months 27 Mbps New building connected Self managed Role in Radio Network • Role in Radio Network – Determines functionality within WLAN – Determines which type of clients will be supported File Server Bridge Workgroup Bridge Bridge Access Point PCI Card PC 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 Bridge roles in the network 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. Bridge roles in the network 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. Bridge roles in the network Non-Root Bridge with Clients • 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. Bridge roles in the network 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. Bridge roles in the network 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 Model Data Rate Max. Distance Miles BR350 Optional Antenna Standard Cable (6.7 dB/100 ft. loss) (6.7 dB/30.5 m) Km 11 Mbps 20.5 33.0 21 dBi Dish 50 ft (15.2m)/side 11 Mbps 32.7 52.5 21 dBi Dish 20 ft (6.1m)/side 5.5 Mbps 32.6 52.4 21 dBi Dish 50 ft (15.2m)/side 2 Mbps 41.0 66.0 21 dBi Dish 50 ft (15.2m)/side 1 Mbps 51.7 83.2 21 dBi Dish 50 ft (15.2m)/side Note: Distances over 25 miles or 40 Km are very hard to align and install! 802.11b Common Questions Cisco Aironet Bridge How Fast? Max data rate 11 Mbps 2 Mbps Typical throughput 5.5 Mbps 1.4 Mbps How Far? Yagi antenna Dish antenna 3.6 Miles 5.8 Km 20.5 Miles 33 Km 7.3 miles 11.7 Km 25+ miles 40+ Km Note: All distances may be limited by governing bodies and standards. Optional 2.4GHz Antennas for Long Range • 13.5 dBi Yagi Distances over 7.3 miles @ 2 Mbps 3.6 miles @ 11 Mbps • 21 dBi Solid Dish For distances up to 25+ miles @ 2 Mbps 20.5 miles @ 11 Mbps Note: Distances include 50 feet of low loss cable and 10 dB fade margin 802.11b Bridge Application: School District Richardson Elementary Yagi Bode Elementary Yagi WeaverRoberts Special Middle School Education Dish Dish High School 2 Bridges One 12 dBi omni One Dish Channel #1 Channel #6 Channel #11 Price Elementary Yagi UNIVERSITY Administration 2 Bridges One 12 dBi omni One Yagi Lincoln Elementary Yagi Bolich Dewitt Elementary Middle School Yagi Yagi Lightning Lightning Arrestor To Antenna • • 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 Lug Lockwasher Nut Ground Wire From RF Device 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 100 ft (30.5 m)? Towers needed to clear trees and other buildings Coax Length 150 ft (45.7)? Wants 11 Mbps data rate Distance = 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 • 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 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 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 Model Data Rate Max. Distance Miles 1400 Optional Antenna Km 54 Mbps 12 xx.0 28 dBi Dish 9 Mbps 23 xx 28 dBi Dish 54 Mbps 7.5 xx 22 dBi Int. 16 Mbps 9 xx 22 dBi Int. Note: Distances over 25 miles or 40 Km are very hard to align and install! Optional 5GHz Antennas for Long Range • 9.5 dBi sector (H or V polarization) • • • • 9 dBi omni (Vertical polarization) • • • 28 dBi dish (H or V polarization) 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 oC Humidity: 0 to 100% Bridge Range Calculation Utility Bridge Distance Calculations (cont.) Bridge Distance Calculations (cont.)