© 2007 Cisco Systems, Inc. All rights reserved.DESGN v2.08-1 Identifying Wireless Networking Considerations Designing Wireless Networks with Controllers. - презентация

1 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Identifying Wireless Networking Considerations Designing Wireless Networks with Controllers

2 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Reasons for an RF Site Survey Defines RF characteristics in the environment: –Discover RF coverage areas. –Check for RF interference and issues. –Provide RF spectrum analysis. –Determine appropriate placement of wireless infrastructure devices. Helps define customer requirements

3 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v RF Site Survey Process 1. Define customer requirements. 2. Identify coverage areas and user density. 3. Determine preliminary access point locations. 4. Perform the actual surveying. 5. Document the findings.

4 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v RF Site Survey Customer Requirements What type and number of wireless devices need to be supported? –Is there current WLAN or RF equipment in place? –Will the WLAN be used only for data? –Will wireless phones be supported in the future? –Are there peak periods to support? Will users be stationary or on the move while using the WLAN? Where should wireless coverage support be provided? What level of support should be provided?

5 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v RF Site Survey Identifying Coverage Areas Break Room: Microwave Ovens File Room or Supply Room: Large Filing or Metal Cabinets Stairwells (Reinforced Building Area) Elevator Shafts Test Lab Conference Office Cubicles

6 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Determining Preliminary Access Point Locations Default Access Point Placement

7 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Visualizing RF Coverage

8 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Performing the Site Survey Use tools and processes to determine coverage: Estimate the access point needed using planning. Measure attenuation at the corner and edge of coverage areas. Determine the coverage range. Build the WLAN coverage. Identify coverage holes.

9 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Site Survey Report All information gathered and developed during the site survey should be included in the report: Detail customer requirements. Describe and diagram access point coverage. –Be very specific when describing equipment placement locations. –Mark areas that are covered as well as those not needing coverage. Parts list should include: –Access points –Antennas –Accessories and network components Discuss the tools that were used and survey methods.

10 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Supporting Guest Access

11 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Path Isolation with Ethernet in IP Tunnel Use of EtherIP tunnels to logically segment and transport the guest traffic between edge and anchor controllers Other traffic (employee for example) still locally bridged on the corresponding VLAN No need to define the guest VLANs on the switches connected to the edge controllers Original Ethernet frame from guest maintained across LWAPP and EtherIP tunnels EtherIP supported across all WLAN controllers –2006 WLC cannot anchor EtherIP connections.

12 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Outdoor Wireless Deployment Options

13 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Wireless mesh management system Enables network- wide policy configuration and device management Supports SNMP and syslog Links the wireless mesh access points to the wired network Handles RF algorithms and optimization Seamless Layer 3 Mobility Provides security and mobility management Serves as root or gateway access point to the wired network Typically located on rooftops or towers Connects up to 32 pole-top mesh access points using a Provides b/g client access Connects to root access points via a Takes AC or DC power; PoE capable Ethernet port for connecting peripheral devices Outdoor Wireless Mesh Solution Components Cisco Wireless LAN Controller Rooftop Access Point Mesh Access Point Cisco Wireless Control System

14 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: MAP-to-RAP Connectivity in a Square Mile

15 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Mesh Design Recommendations HopsOneTwoThreeFour Throughput~10 Mbps~5 Mbps~3 MbpsUp to 1 Mbps* Latency < 10 ms per hop, 1–3 ms is typical Hops Outdoor: Code supports up to eight hops; four or fewer hops are recommended. Indoor: One hop is supported. Nodes per RAP One RAP supports up to 32 MAPs; 20 nodes are recommended.

16 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Common Wireless Design Questions How many access points are needed? Where will the access points be placed? How will the access points receive power? How many WLCs are needed? Where should the WLCs be placed?

17 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v LWAPP Access Point Feature Summary 10x0 Models 1121 AG Models 1130 AG Series 1230 AG Series 1240 AG Series 1300 Series 1500 Series Autonomous/LWAPP/bothLWAPPBoth Both (LWAPP in AP mode) LWAPP External antennaYesNo Yes Outdoor installNo Yes REAP or H-REAP supportREAPNoH-REAPNoH-REAPNoYes Dual radioYes No (only g) Yes No (only g) Yes Power (watts) N/A Memory (Mb) WLANs per radio supported

18 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v WLAN Controllers and Access Point Support Part Number (Platform) No. of Access Points Supported AIR-WLC2006-K9 (Cisco Wireless LAN Controller appliance)6 NM-AIR-WLC6-K9 (Cisco Wireless LAN Controller Module for ISRs) 6 WS-C3750G-24WS-S25 (Cisco Catalyst 3750G Integrated Wireless LAN Controller) 25 WS-C3750G-24WS-S50 (Cisco Catalyst 3750G Integrated Wireless LAN Controller) 50 AIR-WLC K9 (Cisco Wireless LAN Controller appliance)12 AIR-WLC K9 (Cisco Wireless LAN Controller appliance)25 AIR-WLC K9 (Cisco Wireless LAN Controller appliance)50 AIR-WLC K9 (Cisco Wireless LAN Controller appliance)100 Cisco Catalyst 6500 Series Wireless Services ModuleUp to 300

19 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Controller Placement Design Minimize intercontroller roaming. Implement deterministic redundancy. Centralized design supports the integrated platforms. –Cisco Catalyst 3750G Integrated Wireless LAN Controller for small-to-medium deployments –Cisco WiSM for medium-to-large deployments Distributed designs may work well with existing networks. General recommendation is to use a centralized design, but decide based on: –Current network and policies –Growth plans

20 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Distributed WLC Design

21 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Centralized WLC Design

22 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Campus WLC Options Stand-alone appliance controller Routed network on another platform 802.1Q trunk to switched or routed network Integrated controller Routed network can exist on the same platform. Layer 2 connection is internal. Layer 2 or 3 connection to routed network can be used.

23 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Branch Wireless Network Design Considerations Number of access points needed at the branch –Availability of switch ports –Availability of power Controller cost WAN bandwidth constraints –Latency between the access point and the WLC should not exceed 200 ms RTT. –For centralized controllers, use REAP or Hybrid REAP access points.

24 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Local MAC Access point MAC functions: : Beacons, probe response control: Packet acknowledgment and transmission e: Frame queuing and packet prioritization i: MAC layer data encryption and decryption MAC management: Association requests and actions Controller MAC functions: proxy association requests and actions e resource reservation i authentication and key management

25 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Remote Edge Access Point Lightweight access point designed to be controlled across WAN links: –REAP is designed to support remote offices by extending LWAPP control timers. –Control traffic is still LWAPP encapsulated and sent to Cisco Wireless LAN Controller. –Client data is not LWAPP-encapsulated but is locally bridged. All management control and RF management is available when the WAN link is up and connectivity is available to the Cisco Wireless LAN Controller. It will continue to provide local connectivity even if the WAN is down.

26 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v REAP Limitations REAP devices do not support 802.1Q trunking. All WLANs terminate on a single subnet. If connectivity to the WLC is lost, only WLAN1 is supported. Multiple WLANs are not recommend on REAP devices. REAP devices support only Layer 2 security policies. REAP devices and clients require a routable IP address provided locally and do not support NAT.

27 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Hybrid REAP H-REAP is a solution for small or branch offices and retail on the LWAPP Cisco IOS platforms H-REAP supports simultaneous tunneling and local bridging. –Local switching supports bridging traffic onto local VLANs. –Central switching supports tunneling traffic to the controller. H-REAP provides more security options for the remote site: –Stand-alone mode does client authentication by itself. (WPA-PSK, WPA-PSK2) –Connected mode uses the controller to complete client authentication. (WPA-PSK, WPA-PSK2, VPNs, L2TP, EAP, and web auth) Round-trip latency must not exceed 200 ms between the access point and the controller. H-REAP supports NAT and PAT.

28 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: H-REAP Deployment

29 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Branch Office WLC Options Appliance controllers Cisco 2006Support for up to six access points Cisco , Integrated controller Cisco Wireless LAN Controller Module for ISR Cisco Catalyst 3750 Series Integrated WLAN Controller (support for 25, 50 access points)

30 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v Summary An RF site survey is used to determine the RF characteristics of a wireless network and help determine access point placement. Guest services are easily supported using EtherIP tunnels in the Cisco Unified Wireless Network. Outdoor wireless networks are supported using outdoor access points and Cisco Wireless Mesh Networking access points. Campus wireless network design provides RF coverage for wireless clients in the campus using lightweight access points. The access points are managed to Cisco Wireless LAN Controllers. Branch wireless network design is provides RF coverage for wireless clients in the branch. Central management of REAP or H-REAP access points can be supported.

31 © 2007 Cisco Systems, Inc. All rights reserved.DESGN v