Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Restrictions for CleanAir
Only Cisco CleanAir-enabled access points using the following access point modes can perform Cisco CleanAir spectrum monitoring:
Local—In this mode, each Cisco CleanAir-enabled access point radio provides air quality and interference detection reports for the current operating channel only.
FlexConnect—When a FlexConnect access point is connected to the controller, its Cisco CleanAir functionality is identical to local mode.
Monitor—When Cisco CleanAir is enabled in monitor mode, the access point provides air quality and interference detection reports for all monitored channels.
The following options are available:
All - All channels
DCA - Channel selection governed by the DCA list
Country - All channel legal within a regulatory domain
Note
Suppose you have two APs, one in the FlexConnect mode and the other in the monitor mode. Also suppose that you have created a profile enabling EAP attack against 802.1x auth. The Airmagnet (AM) tool, which can generate different types of attacks, fails to generate any attack even if you have provided valid AP MAC and STA MAC addresses. But if the AP MAC and STA MAC addresses in the AM tool are swapped, that is, the AP MAC address is specified in the STA MAC field and the STA MAC address is specified in the AP MAC field, then the tool is able to generate attacks, which the AP in the Monitor mode is also able to detect.
Note
The access point does not participate in AQ HeatMap in WCS.
SE-Connect—This mode enables a user to connect a Spectrum Expert application running on an external Microsoft Windows XP or Vista PC to a Cisco CleanAir-enabled access point in order to display and analyze detailed spectrum data. The Spectrum Expert application connects directly to the access point, bypassing the controller. An access point in SE-Connect mode does not provide any Wi-Fi, RF, or spectrum data to the controller. In addition to performing spectrum intelligence, an access point can provide other. See the “Configuring a Spectrum Expert Connection” section on page 13-24 for instructions on establishing a Spectrum Expert console connection.
Controllers have limitations on the number of monitor mode AP’s that they can support. This is because, a monitor mode AP saves data for all the channels.
Controllers have limitations on the number of monitor mode AP’s that they can support. This is because, a monitor mode AP saves data for all the channels.
Spectrum Expert (Windows XP laptop client) and AP should be pingable, otherwise; it will not work.
Access points in monitor mode do not transmit Wi-Fi traffic or 802.11 packets. They are excluded from radio resource management (RRM) planning and are not included in the neighbor access point list. IDR clustering depends on the controller’s ability to detect neighboring in-network access points. Correlating interference device detections from multiple access points is limited between monitor-mode access points.
Spectrum Expert (SE) Connect functionality is supported for local, flexconnect, bridge, and monitor modes. The access point provides spectrum information to Spectrum Expert only for the current channel(s). For local, FlexConnect, and bridge modes, the spectrum data is available for the current active channel(s) and for the monitor mode, the common monitored channel list is available. The access point continues to send AQ (Air Quality) and IDR (Interference Device Reports) reports to the controller and perform normal activities according to the current mode. Sniffer and rogue detections access point modes are incompatible with all types of CleanAir spectrum monitoring.
Information About CleanAir
Cisco CleanAir is a spectrum intelligence solution designed to proactively manage the challenges of a shared wireless spectrum. All of the users of the shared spectrum can be seen (both native devices and foreign interferers). It also enables the network to act upon this information. For example, the interfering device can be manually removed or the system can automatically change the channel away from the interference.
A Cisco CleanAir system consists of CleanAir-enabled access points, wireless controller modules, mobility controllers, mobility anchors and next generation switches. The access points join the mobility controller directly or through the mobility anchor. They collect information about all devices that operate in the industrial, scientific, and medical (ISM) bands, identify and evaluate the information as a potential interference source, and forward it to the controller. The switch controls the access points, collects spectrum data, and forwards information to WCS or a Cisco mobility services engine (MSE) upon request.
Any networking configurations can be performed only on the mobility controller, configurations cannot be performed in the MA mode. However, any radio level CleanAir configurations can be done using mobility anchor.
For every device operating in the unlicensed band, Cisco CleanAir tells what it is, where it is, how it is impacting the wireless network, and what actions should be taken. It simplifies RF.
Wireless LAN systems operate in unlicensed 2.4-GHz and 5-GHz ISM bands. Many devices like microwave ovens, cordless phones, and Bluetooth devices also operate in these bands and can negatively affect the Wi-Fi operations.
Some of the most advanced WLAN services, such as voice over wireless and IEEE 802.11n radio communications, could be significantly impaired by the interference caused by other legal users of the ISM bands. The integration of Cisco CleanAir functionality addresses this problem of radio frequency (RF) interference.
The controller performs the following tasks in a Cisco CleanAir system:
Configures Cisco CleanAir capabilities on the access point.
Provides interfaces (GUI, CLI, and SNMP) for configuring Cisco CleanAir features and retrieving data.
Displays spectrum data.
Collects and processes air quality reports from the access point and stores them in the air quality database. Air Quality Report (AQR) contains information about the total interference from all identified sources represented by Air Quality Index (AQI) and summary for the most severe interference categories. The CleanAir system can also include unclassified interference information under per interference type reports which enable you to take action in cases where the interference due to unclassified interfering devices is frequent.
Collects and processes interference device reports (IDRs) from the access point and stores them in the interference device database.
Forwards spectrum data to WCS and the MSE.
Interference Types that Cisco CleanAir can Detect
Cisco CleanAir can detect interference, report on the location and severity of the interference, and recommend different mitigation strategies. Two such mitigation strategies are persistent device avoidance and spectrum event-driven RRM. New
Wi-Fi chip-based RF management systems share these characteristics:
Any RF energy that cannot be identified as a Wi-Fi signal is reported as noise.
Noise measurements that are used to assign a channel plan tend to be averaged over a period of time to avoid instability or rapid changes that can be disruptive to certain client devices.
Averaging measurements reduces the resolution of the measurement. As such, a signal that disrupts clients might not look like it needs to be mitigated after averaging.
All RF management systems available today are reactive in nature.
Cisco CleanAir is different and can positively identify not only the source of the noise but also its location and potential impact to a WLAN. Having this information allows you to consider the noise within the context of the network and make intelligent and, where possible, proactive decisions. For CleanAir, two types of interference events are common:
Persistent interference
Spontaneous interference
Persistent interference events are created by devices that are stationary in nature and have intermittent but largely repeatable patterns of interference. For example, consider the case of a microwave oven located in a break room. Such a device might be active for only 1 or 2 minutes at a time. When operating, however, it can be disruptive to the performance of the wireless network and associated clients. Using Cisco CleanAir, you can positively identify the device as a microwave oven rather than indiscriminate noise. You can also determine exactly which part of the band is affected by the device, and because you can locate it, you can understand which access points are most severely affected. You can then use this information to direct RRM in selecting a channel plan that avoids this source of interference for the access points within its range. Because this interference is not active for a large portion of the day, existing RF management applications might attempt to again change the channels of the affected access points. Persistent device avoidance is unique, however, in that it remains in effect as long as the source of interference is periodically detected to refresh the persistent status. The Cisco CleanAir system knows that the microwave oven exists and includes it in all future planning. If you move either the microwave oven or the surrounding access points, the algorithm updates RRM automatically.
Note
Spectrum event-driven RRM can be triggered only by Cisco CleanAir-enabled access points in local mode.
Spontaneous interference is interference that appears suddenly on a network, perhaps jamming a channel or a range of channels completely. The Cisco CleanAir spectrum event-driven RRM feature allows you to set a threshold for air quality (AQ) that, if exceeded, triggers an immediate channel change for the affected access point. Most RF management systems can avoid interference, but this information takes time to propagate through the system. Cisco CleanAir relies on AQ measurements to continuously evaluate the spectrum and can trigger a move within 30 seconds. For example, if an access point detects interference from a video camera, it can recover by changing channels within 30 seconds of the camera becoming active. Cisco CleanAir also identifies and locates the source of interference so that more permanent mitigation of the device can be performed at a later time.
In the case of Bluetooth devices, Cisco CleanAir-enabled access points can detect and report interference only if the devices are actively transmitting. Bluetooth devices have extensive power save modes. For example, interference can be detected when data or voice is being streamed between the connected devices.
Interference Device Merging
The Interference Devices (ID) messages are processed on a Mobility Controller (MC). The Mobility Anchor
(MA) forwards the ID messages from APs and hence they are processed on the MC. The MC
has visibility of the neighbor information across APs connected to
different MAs.
ID merging logic requires AP neighbor information. Neighbor
information is obtained from the RRM module. This api only gives neighbor
information to the APs directly connected to MC. In order to get
neighbor information for all APs (connected to MC and connected MA)
merging logic needs to use rrm api : XYZ.
Currently the AP neighbor list on MA is synced
to MC once every 3 minutes; hence the AP neighbor list obtained by
this api could be at most 3 mins old. This delay results in delay
in merging of Devices as they are discovered. The subsequent
periodic merge will pick up the updated neighbor information and
merge is performed
Persistent Devices
Some interference devices such as outdoor bridges and Microwave Ovens only transmit when needed. These devices can cause significant interference to the local WLAN due to short duration and periodic operation remain largely undetected by normal RF management metrics. With CleanAir the RRM DCA algorithm can detect, measure, register and remember the impact and adjust the DCA algorithm. This minimizes the use of channels affected by the persistent devices in the channel plan local to the interference source. Cisco CleanAir detects and stores the persistent device information in the switch and this information is used to mitigate interfering channels.
CleanAir-capable Monitor Mode access point collects information about persistent devices on all configured channels and store the information in controller. Local/Bridge mode AP detects interference devices on the serving channels only.
Persistent Device Avoidance
When a Persistent Device (PD) is detected in the CleanAir module, it is reported to the RRM module on the MA. This information is used in the channel selection by the subsequent EDRRM signal sent to the RRM module.
EDRRM and AQR Update Mode
AQ reports are only available on the MC. The mode configuration and timers are held in RCB on MA (for APs connected to MA). There is no change to the current API available for EMS/NMS. No change is required for directly connected APs as RCB (spectrum config and timers) is available locally. For remote APs (APs connected to MA), three new control messages are added. These three messages are for enable, restart timer and disable rapid update mode for a given AP MAC address and slot.
CleanAir High Availability
CleanAir configuration (network and radio) is stateful during
the switchover. On the MC, EICORE provides the sync on network configurations
across active and standby nodes. The radio configurations are synced using the
HA Infrastructre. The CleanAir configurations on MA are pulled from the MC upon
joining. The network configuration is not stored in the EICORE on MA, hence
it is synced using HA Infrastructure.
CleanAir Data (AQ and IDR) reports are not stateful, that is, the standby and active nodes are
not synced. On switchover, the APs
send the reports to the current active slot. The RRM Client (HA Infra Client) is used for
CleanAir HA sync.
How to Configure CleanAir
Enabling CleanAir for 2.4-GHz Band
SUMMARY STEPS
1.configureterminal
2.ap dot11 24ghz cleanair
3.end
DETAILED STEPS
Command or Action
Purpose
Step 1
configureterminal
Example:
Switch# configure terminal
Enters global configuration mode.
Step 2
ap dot11 24ghz cleanair
Example:
Switch(config)#ap dot11 24ghz cleanair
Switch(config)#no ap dot11 24ghz cleanair
Enables the CleanAir feature on 802.11b network. Add No in the command to disable CleanAir on the 802.11b network.
Step 3
end
Example:
Switch(config)# end
Returns to privileged EXEC mode. Alternatively, you can also press Ctrl-z to exit global configuration mode.
Configuring a CleanAir Alarm for 2.4-GHz Air-Quality and Devices
Switch(config)#ap dot11 24ghz rrm channel cleanair-event sensitivity high
Configures the EDRRM sensitivity of cleanair-event.
High– Specifies the most sensitivity to non Wi–Fi interference as indicated by the air quality (AQ) value.
Low– Specifies the least sensitivity to non Wi–Fi interference as indicated by the AQ value.
Medium– Specifies medium sensitivity to non Wi–Fi interference as indicated by the AQ value.
Step 4
end
Example:
Switch(config)# end
Returns to privileged EXEC mode. Alternatively, you can also press Ctrl-z to exit global configuration mode.
Configuring Persistent Device Avoidance
SUMMARY STEPS
1.configureterminal
2. ap dot11 24ghz | 5ghz rrm channel device
3.end
DETAILED STEPS
Command or Action
Purpose
Step 1
configureterminal
Example:
Switch# configure terminal
Enters global configuration mode.
Step 2
ap dot11 24ghz | 5ghz rrm channel device
Example:
Switch(config)#ap dot11 24ghz rrm channel device
Enables the persistent non Wi–Fi device avoidance in the 802.11 channel assignment. Add the No form of the command to disable the persistent device avoidance.
Step 3
end
Example:
Switch(config)# end
Returns to privileged EXEC mode. Alternatively, you can also press Ctrl-z to exit global configuration mode.
Monitoring Various CleanAir Parameters
Table 1 Commands for monitoring CleanAir
Commands
Description
show ap dot11 24ghz cleanair air-quality summary
Displays CleanAir Air Quality (AQ) data for 2.4-GHz band
show ap dot11 24ghz cleanair air-quality worst
Displays CleanAir Air Quality (AQ) worst data for 2.4-GHz band
show ap dot11 24ghz cleanair config
Displays CleanAir Configuration for 2.4-GHz band
show ap dot11 24ghz cleanair device type all
Displays all CleanAir Interferers for 2.4-GHz band
show ap dot11 24ghz cleanair device type bt-discovery
Displays CleanAir Interferers of type BT Discovery for 2.4-GHz band
show ap dot11 24ghz cleanair device type bt-link
Displays CleanAir Interferers of type BT Link for 2.4-GHz band
show ap dot11 24ghz cleanair device type canopy
Displays CleanAir Interferers of type Canopy for 2.4-GHz band
show ap dot11 24ghz cleanair device type cont-tx
Displays CleanAir Interferers of type Continuous TX for 2.4-GHz band
show ap dot11 24ghz cleanair device type dect-like
Displays CleanAir Interferers of type DECT Like for 2.4-GHz band
show ap dot11 24ghz cleanair device type fh
Displays CleanAir Interferers of type 802.11FH for 2.4-GHz band
show ap dot11 24ghz cleanair device type inv
Displays CleanAir Interferers of type WiFi Inverted for 2.4-GHz band
show ap dot11 24ghz cleanair device type jammer
Displays CleanAir Interferers of type Jammer for 2.4-GHz band
show ap dot11 24ghz cleanair device type mw-oven
Displays CleanAir Interferers of type MW Oven for 2.4-GHz band
show ap dot11 24ghz cleanair device type nonstd
Displays CleanAir Interferers of type WiFi Inv. Ch for 2.4-GHz band
show ap dot11 24ghz cleanair device type persistent
Displays CleanAir Interferers of type Persistent for 2.4-GHz band
show ap dot11 24ghz cleanair device type superag
Displays CleanAir Interferers of type SuperAG for 2.4-GHz band
show ap dot11 24ghz cleanair device type tdd-tx
Displays CleanAir Interferers of type TDD Transmit for 2.4-GHz band
show ap dot11 24ghz cleanair device type video
Displays CleanAir Interferers of type Video Camera for 2.4-GHz band
show ap dot11 24ghz cleanair device type wimax-fixed
Displays CleanAir Interferers of type WiMax Fixed for 2.4-GHz band
show ap dot11 24ghz cleanair device type wimax-mobile
Displays CleanAir Interferers of type WiMax Mobile for 2.4-GHz band
show ap dot11 24ghz cleanair device type xbox
Displays CleanAir Interferers of type Xbox for 2.4-GHz band
show ap dot11 24ghz cleanair device type zigbee
Displays CleanAir Interferers of type zigbee for 2.4-GHz band
show ap dot11 5ghz cleanair air-quality summary
Displays CleanAir Air Quality (AQ) data for 5-GHz band
show ap dot11 5ghz cleanair air-quality worst
Displays CleanAir Air Quality (AQ) worst data for 5-GHz band
show ap dot11 5ghz cleanair config
Displays CleanAir Configuration for 5-GHz band
show ap dot11 5ghz cleanair device type all
Displays all CleanAir Interferers for 5-GHz band
show ap dot11 5ghz cleanair device type canopy
Displays CleanAir Interferers of type Canopy for 5-GHz band
show ap dot11 5ghz cleanair device type cont-tx
Displays CleanAir Interferers of type Continuous TX for 5-GHz band
show ap dot11 5ghz cleanair device type dect-like
Displays CleanAir Interferers of type DECT Like for 5-GHz band
show ap dot11 5ghz cleanair device type inv
Displays CleanAir Interferers of type WiFi Inverted for 5-GHz band
show ap dot11 5ghz cleanair device type jammer
Displays CleanAir Interferers of type Jammer for 5-GHz band
show ap dot11 5ghz cleanair device type nonstd
Displays CleanAir Interferers of type WiFi Inv. Ch for 5-GHz band
show ap dot11 5ghz cleanair device type persistent
Displays CleanAir Interferers of type Persistent for 5-GHz band
show ap dot11 5ghz cleanair device type superag
Displays CleanAir Interferers of type SuperAG for 5-GHz band
show ap dot11 5ghz cleanair device type tdd-tx
Displays CleanAir Interferers of type TDD Transmit for 5-GHz band
show ap dot11 5ghz cleanair device type video
Displays CleanAir Interferers of type Video Camera for 5-GHz band
show ap dot11 5ghz cleanair device type wimax-fixed
Displays CleanAir Interferers of type WiMax Fixed for 5-GHz band
show ap dot11 5ghz cleanair device type wimax-mobile
Displays CleanAir Interferers of type WiMax Mobile for 5-GHz band
The Cisco Support website provides extensive online resources,
including documentation and tools for troubleshooting and
resolving technical issues with Cisco products and technologies.
To receive security and technical information about your
products, you can subscribe to various services, such as the
Product Alert Tool (accessed from Field Notices), the Cisco
Technical Services Newsletter, and Really Simple Syndication
(RSS) Feeds.
Access to most tools on the Cisco Support website requires a
Cisco.com user ID and password.