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User Guide for the CiscoWorks WLSE and WLSE Express, 2.15
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Preface
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Getting Started
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Using the Deployment Wizard
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Fault Monitoring
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Device Discovery and Management
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Using IOS Templates
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Using WLSM Templates
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Using Wizard Templates
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Managing Device Configurations
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Upgrading Device Firmware
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Using Reports
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Configuring Your WLAN Radio Environment
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Managing Your WLAN Radio Environment
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Managing Your WLAN Radio Environment by Sites
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Using the Intrusion Detection System
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Managing Your Voice Network
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Managing the WLSE System
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Managing the WLSE System via the CLI
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Using the Internal AAA Server (WLSE Express Only)
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Command Line Interface (CLI) Commands
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Naming Guidelines
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Ports and Protocols
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Glossary
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Index
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Table Of Contents
Configuring Your WLAN Radio Environment
Enabling and Disabling Radio Management Features
Disabled Radio Management Related Faults
Configuring Your Network for Radio Management
Understanding Radio Management
What is WDS and Why Do I Need It?
Understanding WDS Access Points
Understanding WLSM WDS Devices
Understanding Radio Performance—Coverage and Capacity
Understanding Frequency and Transmit Power Planning
Collecting Radio Location Data
Configuring Your WLAN Radio Environment
The following topics provide information about the WLSE radio environment:
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Enabling and Disabling Radio Management Features
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WLSE Radio Management
The WLSE simplifies the deployment, expansion, and day-to-day management of your WLAN radio environment. Using radio management, intrusion detection, and site management features, you can:
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To set up and manage your WLAN radio environment, use the features provided by the Radio Manager, Sites, and the Intrusion Detection System:
Figure 11-1 Radio Management Setup Overview
Step 1: Configure your network for radio management
All the device information shown under the Radio Manager, Sites, and Intrusion Detection Services tabs is polled from the managed devices in your network. The WLSE polls and receives aggregated data from WDS devices and provides intelligent processing of this data. The WLSE can manage multiple subnets, so it can receive radio frequency data from many WDS devices.
The WLSE must register with each WDS in each managed AP subnet to receive radio frequency data. If the WLSE is not registered, none of the Radio Manager, Sites, or Intrusion Detection System functions will work.
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In addition, if Radio Management has been disabled, none of the Radio Manager functions will work. You must enable Radio Management to access the Radio Manager features (see Enabling and Disabling Radio Management Features).
For more information about preparing your network to manage radio devices, see:
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Step 2: Collect radio location measurements.
After the access points have been configured for radio management, you can use selections under the Radio Manager and Sites tabs to gather radio location measurements. The WLSE uses these measurements to characterize the radio environment and determine the channels and power limits for each 802.11 Basic Service Set (BSS).
To collect this data, you can either:
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For more information about collecting and managing radio location measurements, see:
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Step 3: Generate optimal radio parameters values for the APs.
You can use the selections under the Radio Manager or Sites tabs to recommend optimal radio transmit power, channel selection, and beacon interval (optional) for each AP, then apply these configuration settings.
To generate these parameters, you can either:
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For more information about generating AP radio parameters, see Generating Radio Parameters.
Step 4: Manage your WLAN network.
After you have configured your network for radio management, collected the radio location data, and generated the radio parameters, you are ready to manage your WLAN environment. You can:
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Related Topics
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Enabling and Disabling Radio Management Features
WLSE Radio Management includes three major groups of features: the Intrusion Detection System (IDS), the Radio Manager (Radio Mgr), and the Site planning features (Sites, including Location Manager). By default, these features are automatically enabled. However, customers that have large, distributed, or staged deployments of wireless solutions might only require the fault, performance, and configuration management features of WLSE and will want to disable Radio Management.
The following topics provided more information about disabling Radio Management:
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Using the CLI Command
The following CLI command will enable or disable Radio Management and restart the WLSE:
radiomanager enable | disable
Enabling or disabling Radio Management causes the WLSE to reload. For more information about this command, see Command Line Interface (CLI) Commands, radiomanager.
Disabled Radio Management Related Faults
When Radio Management is disabled, no new Radio Management related faults are generated, and any Radio Management related faults that existed before the command was executed must be cleared manually. After the faults are manually cleared, they are not regenerated even if the fault condition still exists.
When Radio Management is disabled, the following faults are no longer generated:
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Configuring Your Network for Radio Management
Before you can use the Radio Management features provided by WLSE, you must configure your network. If your network is not properly configured, none of the Radio Manager, Sites, or Intrusion Detection System functions will work.
If you are configuring APs or WLSM devices as WDS devices, you can use the Deployment Wizard (see Using the Deployment Wizard). The Deployment Wizard replaces many of the manual configuration procedures that are normally required to configure infrastructure access points and WDS devices and to configure the WLSE to discover and manage those devices.
Although you can use the Deployment Wizard to set up most APs, you must use the following manual procedure to configure an external ACS server for AP-WDS-WLSE authentication.
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Procedure
Step 1
Step 2
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For more information about configuring AP-WDS devices, see the "Radio Management Setup—IOS Devices" chapter in Configuring Devices for Management by the CiscoWorks Wireless LAN Solution Engine, 2.15. For information about locating this document, see Finding WLSE Documentation on Cisco.com.
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Step 3
For information about radio management configuration procedures, see the "Radio Management Setup—IOS Devices" chapter in Configuring Devices for Management by the CiscoWorks Wireless LAN Solution Engine, 2.15.
To verify that you have correctly configured the network for radio management, use the Verify RM Capability option under the Sites tab (see Verifying Radio Management Capability).
Step 4
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For more information about enabling LEAP authentication, see the Configuring Devices for Management by the CiscoWorks Wireless LAN Solution Engine, 2.15. For information about locating this document, see Finding WLSE Documentation on Cisco.com.
Step 5
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You can also verify this setting by running the "show wlccp wnm status" command on the active WDS in enable mode. A typical output would look like this:
NMS-AP1200-1#show wlccp wnm statusWNM IP Address: 172.16.0.0 Status: SECURITY KEYS SETUPwhere:
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Step 7
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You can also verify this setting by running the "show wlccp wds ap" CLI command on the active WDS in enable mode.
Step 8
For information about configuring the ACS server to support roaming and simultaneous logins, see the ACS server documentation. For other information about configuring the ACS server, see the "Setting Up an ACS Server" chapter in Configuring Devices for Management by the CiscoWorks Wireless LAN Solution Engine, 2.15. For information about locating these documents, see Finding WLSE Documentation on Cisco.com.
Step 9
For information about configuring the AAA server to multiple logins, see the AAA server documentation. For other information about configuring the AAA server, see the "Setting Up an ACS Server" chapter in Configuring Devices for Management by the CiscoWorks Wireless LAN Solution Engine, 2.15. These documents are also located on Cisco.com.
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Related Topics
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Understanding Radio Management
The radio management environment provided by WLSE consists of:
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Figure 11-2 WLSE Radio Management Environment
The following topics describe how the WLSE implements radio management:
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What is WDS and Why Do I Need It?
The critical software component in the network is a set of IOS features called the Wireless Domain Services (WDS). The following types of devices can supply the WDS:
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Each WDS access point supports one AP subnet. You can add additional WDS access points for redundancy. The priorities you set on the WDS access points determine which one is the active and which ones are backups.
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Each WLSM supports multiple AP subnets, as long as all of the subnets are served by the switch on which the WLSM is installed.
The following topics describe these devices types:
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Understanding WDS Access Points
The WDS provides control path technologies that must be active on an AP in each AP subnet; a backup WDS can also be defined in each AP subnet. The WDS provides:
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There is no RM data aggregation without a WDS. Without a WDS, the communication between the access points and WLSE looks like this:
Figure 11-3 Basic Network Management Communications
Using this approach, the WLSE can communicate with the APs using only these two methods:
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Caution
After you configure the network for Radio Management tasks (see Configuring Your Network for Radio Management), the WLSE communicates all Radio Management activities with one or more WDS APs instead of all APs in the network. Each WDS AP collects data from other wireless clients in the network and sends this aggregated data to the WLSE.
Figure 11-4 Additional Radio Management Communications
Understanding WLSM WDS Devices
A Wireless LAN Services Module (WLSM) device is a module for the Cisco Catalyst 6500 Series switch that provides WDS to the wireless network. Each WLSM supports multiple AP subnets, as long as all of the subnets are served by the switch on which the WLSM is installed.
You can add a second WLSM to serve as a standby. The WLSE authenticates with both the HSRP active and HSRP standby WLSM devices (WLSM uses HSRP to handle redundancies). In the reports, both WLSM devices (HSRP active and HSRP standby) will appear as active WDSs.
If the HSRP active WLSM goes down, the HSRP standby WLSM will communicate with the AP subnets (see Figure 11-5).
Figure 11-5 WLSE-WLSM Communications
Figure 11-6 illustrates a network that uses both AP and WLSM WDS devices to manage the access points in the network. In this example, additional access points have been identified as backup AP-WDS devices (AP1 and AP4), and an additional HSRP-based WLSM-WDS device has been added to as a standby for the active WLSM-WDS.
Figure 11-6 Sample Network Using AP-WDS and WLSM-WDS Devices
Understanding Radio Performance—Coverage and Capacity
The Radio Manager:
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Each region is defined by the rough degree of contention and packet collisions experienced by clients in the region due to traffic outside of the BSS.
The inter-BSS contention and collision translates into performance degradation, which the Radio Manager estimates for all potential clients within the region. Contention and collisions from managed APs and rogue and friendly APs are used in the performance evaluation.
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The types and sizes of performance regions determine the expected maximum, minimum, and average performance of a particular domain.
AP/Client Relationships
The Radio Manager acquires knowledge of the WLAN radio environment from measurements obtained from Cisco APs and Cisco clients. Figure 11-7 illustrates the relationships between three APs and their clients.
Figure 11-7 AP/Client Relationships
In this example, the measuring client and one other client are associated with AP A, but neither client detects the other AP's signal. AP B is close enough to be detected by the measuring client, and AP C is out of range, but the measuring client does detect some of AP C's associated clients. Table 11-1 describes these relationships in more detail.
Table 11-1 AP/Client Relationships
The measuring client identifies access point B as a source of 802.11 contention.
The measuring client detects contention from a client in another BSS and identifies access point C as the BSS access point.
The measuring client reports significant contention due to clients in another BSS. Access point C is identified as the BSS access point.
The measuring client indicates intermittent non-802.11 interference and describes the statistics of its received strength.
The measuring client identifies another client in its BSS that appears to be hidden from it.
Radio Performance Regions
Radio performance regions within a BSS depend on the placement and transmit power of other co-channel APs. The transmit power of a BSS defines a set of RF reception rings around its AP (see Figure 11-8).
Figure 11-8 RF Reception Rings
Two rings correspond to the downlink:
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Two similar rings correspond with areas of reception and the RF influence emanating from a client positioned at the edge of the BSS coverage ring. The significant ring, the uplink RF influence ring (4), corresponds to the signal that originates from a client sending packets up to its AP.
Uplink Contention Regions
In Figure 11-9, AP1 and AP2 share the same channel. AP2 is examined as the BSS of interest, while AP1 is the cochannel neighbor. The highlighted performance region corresponds with an area in which BSS2 clients must contend with traffic from BSS1. The source of contention is shown as a set of clients in BSS1 near the edge of their planned coverage ring. This is known as uplink contention because it delays uplink traffic from clients to their AP.
Figure 11-9 Sample Performance Region
BSS2 performance region: AP2 clients that experience contention from AP1's clients
Source of contention: AP1 clients that cause the contention.
If AP2 has neighbors sharing the same channel on all sides, then similar uplink contention regions are defined in the direction of each neighboring AP. If any of these neighbors is closer than the one shown in Figure 11-9 or uses a higher power limit, then the uplink contention region is larger than shown in the figure. If clients of the neighboring BSSs are close enough to be detected by AP2, then AP2 experiences downlink contention due to the clients' traffic.
The BSS may also contain regions in which a client receives traffic that has collided with packets from another station. This occurs when the intended source and interfering source do not detect each other. This happens when:
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This situation can be remedied by blocking out time for an access point using RTS/CTS (request-to-send, clear-to-send) commands.
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This situation is an inter-BSS interference problem that could exist in any dense WLAN and cannot be remedied with RTS/CTS. One goal of the Radio Manager is to minimize this occurrence with good radio configurations.
Understanding Multiple BSSIDs
The Base Service Set Identifier (BSSID) is typically the MAC address of the radio. WLSE also supports multiple BSSIDs (MBSSID) on a single radio (AP). MBSSIDs address several issues:
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To a client, an MBSSID AP appears to be several distinct co-located APs. An MBSSID AP transmits a beacon for each BSSID/SSID, which makes all of the SSIDs visible for passive scanning. The distinct VLAN multicast streams are easily separated using the BSSID, which allows multiple unencrypted multicast streams and eliminates the decryption errors that occur with encryption separation.
To the WLSE, the MBSSID AP appears to be one AP. Each radio that is configured with MBSSID will appear as one radio with multiple VLANs, and each distinct MAC address associated with the VLAN is considered a synonym of the real radio's MAC address.
Support for multiple BSSIDs does not imply full virtual AP capability and functionality. For example:
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Understanding Frequency and Transmit Power Planning
The Radio Parameter Generation algorithm in WLSE gives you a near-optimal frequency and power plan for managed APs. However at first look, the WLSE-recommended plan might be dramatically different from what you expect.If you have an understanding of 2G cellular technology, particularly GSM, it's important to know that the intuitive heuristics developed from 2G cellular telephony are misleading for WLANs.
In traditional 2G deployments, you design your power plan by making sure adjacent and nearby cells are on differing channels.
In 802.11 WLAN, the closest distance between two co-channel APs is less important than the total number of interfering APs in the entire coverage area.
There are significant differences in 2G and 802.11 WLANs:
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Collecting Radio Location Data
Radio location measurements characterize the radio environment and provide the information other Radio Manager features require to determine the channels and power limits for each Basic Service Set (BSS). To gather these measurements:
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If you do not perform a client walkabout, you must enter a floor plan that includes the distances between APs (see Adding Floors to Location Manager).
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You can also use the Assisted Site Survey wizard, which is part of Sites, to walk you through the process of determining the optimal radio transmit power and channel selection. This wizard interface steps you through AP radio scan, client walkabout, and radio parameter generation (see Using the Location Manager Assisted Site Survey Wizard).
Related Topics
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