Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Different QoS values in the same WLAN


Now, with all the unified communications, voice, video and data are in the same device, and I try to give priority to voice and some applications, but in the WLC I can not find the way to mark all that kind of packets.

Is it possible to do that? like in a LAN making the marking as voice, signaling and any kind of application? as I marked in all the LAN.

the equipment:

WLC 5508  v7.0.116

AP  1142N

Thanks in Advance !


Everyone's tags (2)
Hall of Fame Super Silver

Different QoS values in the same WLAN

I too would like to see how this is being handled or possible in the future, especially with all thoes dang soft phones:)

*** Please rate helpful posts ***
Cisco Employee

Different QoS values in the same WLAN

There is a major problem with that. I would give wrong expectations to people.

If the WLC allowed to mark some type of traffic (statically defined), people would expect QoS to be implemented and to work fine. However, this is what would happen :

-client pc sends untagged traffic

-traffic navigates network to WLC

-WLC marks traffic with QoS

-Traffic continues to other phone

The most critical part is the wireless part and the packet would have still zero priority over wireless.

otherwise you can take a look at sip snooping on the wlc

New Member

Different QoS values in the same WLAN

Hi all,

thanks for you comments!

Ok, at this moment it is not possible to do the QoS thing!

Do you have any suggestion, my wireless network it is slow, all the client complain about that.

Thanks in Advance !

Different QoS values in the same WLAN

Hi Nick,

Follow me here i want to make sure i understand....

1 laptop with a soft phone and web browser example...

Soft phone:

The app would mark the traffic as EF. It does it 802.11e magic. Hits the AP. The AP translates the EF and marks the CAPWAP packet. It hits the WLC which is marked at 6 and the packet hits the wire at 6.

Web Browser:

The browser traffic wouldnt be marked. It goes across the wireless. The ap gets the frame and sees no markings and doesnt mark the capwap. The packet hits the WLC and then marks it as 6 as well?

Am I understanding that right ?


__________________________________________________________________________________________ "Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin ___________________________________________________________
Cisco Employee

Re: Different QoS values in the same WLAN

99% right.

For the soft phone scenario, if the app only marks the packet as EF, the AP doesn't do anything about it. Only when the WLC releases the packet on the LAN will the packet be prioritized with its layer 3 EF tag.

Serious soft phone applications will particulary mark the frame with 802.11e tag 5 (voice) so the wireless drivers really sends it with priority over other data frames. The AP receives it and puts the corresponding EF on the capwap packet.

Softphones who send with the 802.11 tag5 obviously also mark the layer 3 as EF for later on in the network ...

I think what most people don't realize is that there is a difference with Wireless Qos.

Wired QoS = When receiving the packet, the network device will treat that packet in priority when it is tagged

Wireless QoS = Tagged packets actually use more aggressive timers (that would normally violate the medium access rules of normal non-qos 802.11) so that statistically a voice packets will be sent most of the time before anyone else can send a data packet. The goal is that, since it's a shared medium and you maybe have 10 hardcore downloaders doing FTP, you want to cheat a bit by sending your voice packets before they had a chance to send their data packets.

So Wireless QoS adds the opportunity for a voice packet to be sent before any other data packet on a shared medium.

CreatePlease login to create content