QoS Policy for LWAPP/CAPWAP

[j-shearer]

The reason for this post is to retrieve some information on how to go about configuring a QoS policy for LWAPP/CAPWAP.

Currently, we have a 'hub-and-spoke' topology with one hub location and six spoke sites. Each spoke site has a 100Mbps link through our ISP to a single 1GB link at our hub site. We currently deploy a WLC4402 (running v6.0.182.0) at the hub site. The hub site and each spoke site contains a 3560 that is performing L3 functionality. We are planning on deploy approximately 30 1252 LW APs across our six spoke locations. These LW APs will run in H-REAP mode. We wanted to make sure that CAPWAP traffic to/from these APs gets priority (or a certain amount of bandwidth reserved) when communicating back to the centralized WLC.

Does anyone have any configuration examples of this type of scenario or can anyone point me in the right direction as far as documentation?

Any information would be greatly appreciated.

Thx in advance.

Joe

[sebastiaannoppe]

It all depends on how you configure your Wifi :-)

First of all :

LWAPP control frames require prioritization, and LWAPP control frames are marked with a DSCP classification of CS6 , so thats already one to configure.

For LWAPP data packets, it goes something like this :

• WMM-enabled clients have the classification of their frames mapped to a corresponding DSCP classification for LWAPP packets to the WLC. This mapping follows the standard IEEE CoS-to-DSCP mapping, with the exception of the changes necessary for QoS baseline compliance. This DSCP value is translated at the WLC to a CoS value on 802.1Q frames leaving the WLC interfaces.
• Non-WMM clients have the DSCP of their LWAPP tunnel set to match the default QoS profile for that WLAN. For example, the QoS profile for a WLAN supporting 7920 phones would be set to platinum, resulting in a DSCP classification of EF for data frames packets from that AP WLAN.

• LWAPP data packets from the WLC have a DSCP classification that is determined by the DSCP of the wired data packets sent to the WLC. The 80211.e classification used when sending frames from the AP to a WMM client is determined by the AP table converting DSCP to WMM classifications.

Additionally :

LWAPP 802.11 traffic can be divided generally into the following two additional types:

•802.11 management frames—802.11 management frames such as probe requests, and association requests and responses are classified automatically with a DSCP of CS6.

•801.11 data frames—Client data and 802.1X data from the client is classified according to the WLAN QoS settings, but packets containing 802.1X frames from the WLC are marked CS4. 802.11 data traffic classification depends on the QoS policies applied in the WLAN configuration, and is not automatic. The default classification for WLAN data traffic is best-effort.

I am aware that you are using a controller and AP's who will perform CAPWAP but everything said here is valid for that setup as well.

A good reference for this is still : http://www.cisco.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/ch5_QoS.html

It has examples of configuration as it is valid for CAPWAP, except for the ports 12223 & 12222. In CAPWAP, this becomes 5246 & 5247

Hope this helps.