Wireless LAN bridge
© 2004, Cisco Systems, Inc. All rights reserved.
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Bridge basics
• Wireless bridge :work at data link layer (layer 2 of
OSI model)
• Wireless bridge: is a device that connect two or
more networks that may use the same or different
data link layer protocol located in different
buildings.
• Keep traffic separated on both sides of the bridge.
• Deliver high data rate .
• Transmit packet simultaneously without causing
collision.
© 2004, Cisco Systems, Inc. All rights reserved.
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Types of WLAN bridge
1- Basic Ethernet – to - wireless
Connect directly to a single device by an Ethernet port , then provide
wireless connection to an access point
The single device such as (printer, PC) has Ethernet port and no
wireless NIC.
This offer substitute for a radio NIC.
2- Work group bridge
Connecting of wireless network to large wired network.
-Work group bridge act as wireless client on the wireless LAN and then
interfaces to a wired network
-- The advantages of Work group bridge is offering high management and
security.
-The disadvantages of work group bridge is t‫ا‬he higher price.
© 2004, Cisco Systems, Inc. All rights reserved.
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Types of WLAN bridge
3-Access Point (AP) / Wireless bridge
Some access point can be configured as a bridge.
-Can be operate:
-1- Point – to – point
-2- Point- to – multipoint
-Advantages of wireless bridge
-1- Very practical
-2- Extend the range of existing WLANs
-3- Easy to configure
© 2004, Cisco Systems, Inc. All rights reserved.
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Point – to – point wireless bridge
-If there is a company contain of two buildings, the two buildings are
separated by a road
-The options for connecting any two building with network link include .
1-Direct connect private cabling (like fiber)
When using fiber cables and connect it under road it costs higher price.
2- Leased line telecom
It works good but with higher cost and limited bandwidth.
3- Wireless technology
It is the excellent choice .
© 2004, Cisco Systems, Inc. All rights reserved.
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Point – to – point wireless bridge
Point -to -Point (PTP) Bridging:
A point to point topology is the simplest to configure and connects two
networks in two separate locations, normally a remote building or
warehouse, via one wireless bridge in each location.
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Point-to-point configuration
•When using point-to-point wireless bridges, two LANs can be
located up to 40 km (25 miles) apart.
Obstacles such as buildings, trees, and hills will cause communication
problems.
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Point – to – point wireless networking
Advantages of Point – to – point wireless bridge :
1- Good bandwidth (11 – 54 mbps) that run most application.
2- Cheap.
3- Portable
The wireless equipment be moved when you leave.
Disadvantages of Point – to – point wireless bridge:
1- Reliability problem.
2- Must have wireless expertise
© 2004, Cisco Systems, Inc. All rights reserved.
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Point – to – multipoint wireless bridge
•Point – to – multipoint wireless bridge : the solution for
creating a wireless Ethernet like multiple location .
•A point to Multipoint topology wirelessly connects multiple
locations together allowing them to share the same network
resources.
• The bridge at the main, central, location is called the root
bridge or base station bridge and all data passing between the
wireless bridge clients must pass through the root bridge first.
© 2004, Cisco Systems, Inc. All rights reserved.
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Point-to-multipoint configuration
root
Non-root
Non-root
•For multipoint bridging, an omni directional antenna is typically used at
the main site.
•Directional antennas are used at the remote sites.
•Traffic from one remote site to another will be sent to the main site and then
forwarded to the other remote site.
•Remote sites cannot communicate directly with one another.
•Line of sight must be maintained between each remote site and the
main site.
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Point – to – multipoint wireless bridge
These point-to-multipoint networks are used in wireless internet
service providers (WISP), large corporate campuses, distribution
facilities, school districts, public safety applications and many others
Advantages:
Low cost
High speed
© 2004, Cisco Systems, Inc. All rights reserved.
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Root modes
• Cisco Aironet access points and bridges have two different root modes,
in which to operate the following:
Root = ON —
The bridge or AP is a root.
If it is a bridge, then it is called the master bridge.
Root = OFF —
The bridge or AP is not a root, non-root.
© 2004, Cisco Systems, Inc. All rights reserved.
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What do I need to build a Point to Point Bridge Link?
Line of sight between the two locations. A site survey is recommended before
installation.
Select a wireless bridge: Here are some things to consider when selecting a
wireless bridge :
Distance: Distance will determine what gain antenna will be required .
Wireless protocol: Do you want to use a bridge base on 802.11 standards .
Frequency
Indoor or Outdoor: Indoor wireless bridges are less expensive . An outdoor
bridge can be placed right next to the antenna and therefore cuts down on the
amount of cable you need to buy.
Select a wireless antenna: If the bridge you selected does not already have an
integrated antenna you will need to choose one now.
antenna cables to get you connected and protected.
© 2004, Cisco Systems, Inc. All rights reserved.
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Connecting to the bridge
When the bridge is powering up there are three LEDs:
Green LED : indicate normal activity
Red LED : the unit isn’t operating correctly
Amber LED: indicate error or warning
Ways of configuration :
1- Configuring using GUI (through web browser)
2- Configuring using CLI
3- Accessing through telnet
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