© 2006 Cisco Systems, Inc. All rights reserved.BCMSN v3.06-1 Wireless LANs Describing WLAN Topologies. - презентация

1 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Wireless LANs Describing WLAN Topologies

2 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v WLAN Topologies Wireless client access –Mobile user connectivity Wireless bridging –LAN-to-LAN connectivity Wireless mesh networking –Combination of bridging and user connectivity

3 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v WLAN and LAN

4 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Service Set Identifier (SSID) SSID is used to logically separate WLANs. The SSID must match on client and access point. Access point broadcasts one SSID in beacon. Client can be configured without SSID. Client association steps: 1. Client sends probe request. 2. A point sends probe response. 3. Client initiates association. 4. A point accepts association. 5. A point adds client MAC address to association table.

5 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v WLAN Access Topology

6 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Wireless Repeater Topology

7 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Workgroup Bridge Topology

8 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Alternative Peer-to-Peer Topology

9 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Service Sets and Modes Ad hoc mode Independent Basic Service Set (IBSS) –Mobile clients connect directly without an intermediate access point. Infrastructure mode Basic Service Set –Mobile clients use a single access point for connecting to each other or to wired network resources. Extended Services Set –Two or more Basic Service Sets are connected by a common distribution system.

10 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Roaming Through Wireless Cells

11 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Roaming Through Wireless Cells Roaming

12 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Client Roaming Roaming without interruption requires the same SSID on all access points. Maximum data retry count exceeded Too many beacons missed Data rate shifted Periodic intervals

13 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Layer 2 vs. Layer 3 Roaming

14 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Wireless VLAN Support Multiple SSIDs Multiple security types Support for multiple VLANs from switches 802.1Q trunking protocol

15 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Wireless VLAN Support (Cont.) VLANs propagate across access points. VLAN numbers are unique. Access points handle up to 16 VLANs.

16 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Enterprise Voice Architecture

17 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Wireless Mesh Networking In a mesh network topology, devices are connected with redundant connections between nodes.

18 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Wireless Mesh Networking Mesh access points automatically establish connection to controller. –Rooftop access points (RAP) connect via wired connection. –Mesh access points (MAP) connect via self-configuring backhaul connection. Cisco uses mesh access points. Adaptive Wireless Path (AWP) protocol establishes best path to root. Access point authenticates to controller and downloads configuration and radio parameters.

19 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Adaptive Wireless Path Protocol (AWP) AWP protocol establishes an optimal path to root. Each access point carries a feasible successor or successors if topology or link health changes. AWP uses a parent sticky value to mitigate route flaps.

20 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Key Market Segments for Outdoor Wireless Enterprise outdoor Indoor and outdoor wireless solutions for education customers. Rugged mesh solutions for enterprise customers. Public sector Connecting peripheral devices across the mesh. Establishing hot zones for public safety or municipal departments. Service provider Hot spots become hot zones with Wi-Fi access.

21 © 2006 Cisco Systems, Inc. All rights reserved.BCMSN v Summary Types of WLAN topologies are client access, bridging, and mesh networking. Wireless networks are built with multiple wireless cells. WLAN roaming occurs seamlessly between wireless cells. WLANs support VLANs and QoS. WLAN mesh networks extend the wireless network beyond the boundaries of wired LANs.

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