Application Visibility and Control
Application Visibility and Control (AVC) classifies applications using deep packet inspection techniques with the Network-Based Application Recognition (NBAR) engine, and provides application-level visibility and control (QoS) in wireless networks. After the applications are recognized, the AVC feature enables you to either drop, mark, or police the data traffic.
Using AVC, we can detect more than 1000 applications. AVC enables you to perform real-time analysis and create policies to reduce network congestion, costly network link usage, and infrastructure upgrades.
You can view list of 30 applications in Top Applications in Monitor Summary section of the UI.
AVC DSCP marks only the DSCP of the original packet in the controller in both directions (upstream and downstream). It does not affect the outer CAPWAP DCSP. AVC DSCP is applicable only when the application is classified. For example, based on the AVC profile configuration, if an application is classified as ftp or http, the corresponding DSCP marking is applied irrespective of the WLAN QoS. For downstream, the DSCP value of outer CAPWAP header and inner packet’s DSCP are taken from AVC DSCP. WLAN QoS is only applicable for all traffic from WLC to AP through CAPWAP. It does not change the DSCP of the original packet.
Using AVC rule, you can limit the bandwidth of a particular application for all the clients joined on the WLAN. These bandwidth contracts coexist with per-client downstream rate limiting with per client downstream rate limits that takes precedence over the per-application rate limits.
When you downgrade the controller from 8.0 to any earlier version, the AVC rate limit rules display the action as drop. This action is expected since the AVC rate limit rule is introduced in the controller version 8.0.
AVC is supported in central switching mode on the following controller platforms: Cisco 2504 WLCs, Cisco 5508 WLCs, Cisco Flex 7510 WLCs, Cisco 8510 WLCs, and Cisco Wireless Services Module 2 (WiSM2).
The number of concurrent flows supported for AVC classification on different controller platforms are noted in the following table.
|Cisco WLC Platform||Flow|
|Cisco 2504 WLC||26,250|
|Cisco 5508 WLC||183,750|
|Cisco 8510 WLC||336,000|
|Cisco 5520 WLC||336,000|
|Cisco 8540 WLC||336,000|
Application Visibility and Control Protocol Packs
Protocol packs are a means to distribute protocol updates outside the controller software release trains, and can be loaded on the controller without replacing the controller software.
The Application Visibility and Control Protocol Pack (AVC Protocol Pack) is a single compressed file that contains multiple Protocol Description Language (PDL) files and a manifest file. A set of required protocols can be loaded, which helps AVC to recognize additional protocols for classification on your network. The manifest file gives information about the protocol pack, such as the protocol pack name, version, and some information about the available PDLs in the protocol pack.
The AVC Protocol Packs are released to specific AVC engine versions. You can load a protocol pack if the engine version on the controller platform is the same or higher than the version required by the protocol pack.
AAA override for AVC profiles
The AAA attribute for client or user profile is configured on the AAA server using authentication from RADIUS server or Cisco ACS or ISE. The AAA attribute is processed during layer 2 or layer 3 authentication by the controller and the same is overridden by what is configured on the WLAN.
The AAA AVC profile is defined as a Cisco AV air. The string option is defined as avc-profile-name and this value has to be configured for any AVC profile available in the controller.
This section contains the following subsections: