Field Notice: FN70577 - Regulatory Compliance Issue with AP2800/AP3800/AP4800/AP1560/IW6300 - Software Upgrade Recommended

Access Points (APs) that have installed this software fail to comply with the Dynamic Frequency Selection (DFS) radar detection requirements during normal operation when the devices operate on DFS channels. This is Cisco bug ID CSCvt47413. 

Also, an AP that performs a mandatory Channel Availability Check (CAC) for a channel that requires the use of DFS fails to complete the CAC if the Transmit power is changed during the CAC. The AP initiates beaconing immediately. This is Cisco bug ID CSCvt98797.

Customers who operate APs with this software might be operating in violation of regulatory requirements.

APs use radio spectrum that is regulated by governments, which includes regulators such as the US Federal Communications Commission, the European Commission, or individual national authorities. All APs must adhere to the technical conditions imposed by regulators with respect to radio emissions. One mandatory technical requirement is DFS, which requires that APs operate in portions of the 5 GHz band to listen for civil and military radars, and when radar patterns are detected, to stop transmissions and change channels to avoid co-channel operation with these radars. DFS protects these military and civilian radar systems, which includes safety-of-life systems, from harmful interference.

Software updates made available between February and June 2020 have impacted the ability of the specific devices to properly detect these radar events. As a result, APs that use the specific software version as listed in this document are out of compliance with regulatory requirements. All customers, regardless of location, should take the action recommended in this field notice. U.S.-based customers should also review FCC Enforcement Advisory No. 2019-06.

Specifically, these 5 (five) AP Series are affected: AP2800, AP3800, AP4800, AP1560, and IW6300.

If you do not upgrade to the fixed software version, in some jurisdictions you might be exposed to legal liability. You will be exposed if and only if:

• You operate affected APs, and
• The APs run affected code, and
• Your APs operate on DFS channels now or will in the future.

There is no customer visible symptom.

Solution

Upgrade to a fixed software release based on the guidelines in this table.

Immediate Workaround

Configure all vulnerable deployments not to use DFS channels until the software upgrade can be completed.

• In Radio Resource Management for 5GHz, edit the Dynamic Channel Assignment (DCA) list to remove the DFS channels, and
• Configure any radios with static channel assignment to use non-DFS channels.

For Cisco products, the DFS channels are in 5250 to 5350 MHz (channels 52-64) and in 5470 to 5725 MHz (channels 100-144).

Note: This is intended to be a practical workaround in order to avoid the potential interference described in this field notice.  Upgrade to the fixed software as soon as possible in order to allow you to enable DFS channels after the upgrade is completed.

These methods can be used to find the AP Product IDs (PIDs).

CLI

• From the AireOS CLI, enter the show ap summary command.
• From the AP CLI, enter the show inventory command.
• From the Cisco IOS XE CLI, enter the show ap summary command.

GUI

• From the AireOS Advanced GUI, choose Wireless > All APs.
• From the Mobility Express GUI, choose Monitoring > Access Points. See the Add Model column.
• From the Cisco IOS XE GUI, choose Monitoring > Wireless > AP Statistics.

Visual Inspection