QoS

[mcaoile]

Hi experts,

I have a client that have 4 SSIDs (Executive, Admin, Sales, Guest).  First question, the client wants the users connecting to the Executive SSID to have priority over users connecting to Admin, Sales, Guest SSID and users connecting to Admin SSID to have priority over users connecting to Sales and Guest.  QoS for these SSIDs are set to 'Silver'.  I am thinking of setting Executive SSID to 'Gold' and Admin SSID to 'Platinum' and the other SSIDs to 'Silver'.  Is this the right approach?  How can this be implemented?

Second question, is it possible that a user (CEO) connected to Executive SSID will have priority to a user (Manager) that is also connected to Executive SSID?  If possible, how can this be implemented?

Regards,

Manuelito

[Flavio Miranda]

Hello,

Yes you can.

http://www.cisco.com/c/en/us/td/docs/wireless/controller/7-4/configuration/guides/consolidated/b_cg74_CONSOLIDATED/b_cg74_CONSOLIDATED_chapter_01110.html#d142957e26a1635

Take a look at : "Configuring QoS Profiles (CLI)"

config qos average-realtime-rate {bronze | silver | gold | platinum} {per-ssid | per-client} {downstream | upstream} rate

But, something to take in consideration is: How about QoS in your network infraestructure. It is very important. QoS is  end-to-end  and as such must be consistent between all devices.

[Scott Fella · Accepted solution]

Just to add... QoS only happens when there is congestion. In wireless, you can still oversubscribe the access point.  With QoS, end to end QoS is a requirement, that also means on the wired side. If your using 802.1x authentication, you can also specify the user bandwidth if you want along with specifying it if using local policies which require v7.5.  I haven't ever had to implement this in any of my installs to be honest. Are you currently having issues and that's why you want certain SSID/Users to have priority?  The main thing with QoS is that is requires WMM on the device supplicant. If an executive sends out data and its marked at best effort, well it sent out best effort no matter if you specify the wlan higher. The WLC will not remark the traffic, but it will place a cap on the wlan. You can use AVC to remark traffic, but now your just going to make it messy.

-Scott

[mcaoile]

Hi Scott,

I am not having any issues, it's the client asking if this can be done.  Authentication is by WPA2.  5508 code is 7.6.120.

Regards,

Manuelito

[Scott Fella]

Well it seems like you need to educate the client. Understanding how QoS works and what it can and can't do for you is important. 

-Scott

[Rasika Nayanajith · Accepted solution]

QoS for these SSIDs are set to 'Silver'.  I am thinking of setting Executive SSID to 'Gold' and Admin SSID to 'Platinum' and the other SSIDs to 'Silver'.  Is this the right approach? 

No, QoS profile to be changed depend on the traffic type each SSID carry. For example, if any of these SSID carry voice traffic (that is wireless frame user priority(UP) value of 6), then that SSID has to configured for Platinum profile. This is applicable if you have video (UP=4,5) as well.

If you configure Silver (default), then all your traffic treated as Best effort & no differentiation among data, voice, video traffic from QoS perspective as everything get to DSCP=0 to the wired network. 

Typically guest networks (where you do not run voice/vedio) you can use Bronze profile knowing that delay sensitive application are not running.

Impact of the QoS profile can understand from the below post

http://mrncciew.com/2012/12/02/understanding-wireless-qos-part-3/

How can this be implemented?

There is no proper solution for this & it is nature of wireless (everyone- AP & clinets are equal when it comes to who gets the access to wireless medium to tx).

QoS profile change gives higher priority traffic (like voice/video) more opportunity to access the medium. So it is upto endpoint to correctly classify traffic to get that priority (most of BYOD does not mark UP value correctly even though it is use for voice/video application). In that situation it QoS profile change won't give any benefit natively for those traffic. AVC helps downstream direction traffic (towards client) & upstream traffic only at the WLC.

In converged access solutions (3850,5760)  there is a way to manage bandwidth allocation for SSID, which may help certain level in your case. Refer this for more detail.(you can watch this session from Ciscolive365 for free)

Second question, is it possible that a user (CEO) connected to Executive SSID will have priority to a user (Manager) that is also connected to Executive SSID?  If possible, how can this be implemented?

This is further go into user level QoS changes & only way to give those is assign different QoS policy parameters when they authenticating via RADIUS. As these complicated things, you need to determine whether it is really required to have those differentiation.

HTH

Rasika

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