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 2500 Series
Wireless LAN Controllers, Cisco 5500 Series Wireless LAN Controllers, Cisco
Flex 7500 Series Wireless LAN Controllers, Cisco 8500 Series Wireless LAN
Controllers, and Cisco Wireless Services Module 2 (WiSM2) .
The number of concurrent
flows supported for AVC classification on different controller platforms for
8.0 release are noted in the following table. The absolute maximum number of
flows supported on one platform cannot exceed more than 110% of the numbers
shown in the following table and this 10% extra flows support will happen based
on availability of the free memory in the system.
|Cisco 5500 Series Wireless LAN Controller
|Cisco 2500 Series Wireless LAN Controller
|Cisco 8500 Series Wireless LAN Controller