Wireless QoS, Prioritize traffic for dedicated client

[patrashov88]

Hello!

I read Wireless Qos theory carefully but still can not understand few things.

Cisco Wireless Qos Profile ( platinum, gold bronze) is per SSID. When I chose Platinum profile for specific SSID, does it mean that all traffic from AP to client  that belongs this specific SSID will take precedence over client in different SSID? 

In my case, there is no contention in wired media, but I need solution to prioritize traffic from AP to some clients  only over wireless media. Then, when there will be much clients in the same area connected to the same AP,  I need priority over the air for all traffic goes to this specific client.

Thank you.

[Rasika Nayanajith]

Cisco Wireless Qos Profile ( platinum, gold bronze) is per SSID. When I chose Platinum profile for specific SSID, does it mean that all traffic from AP to client  that belongs this specific SSID will take precedence over client in different SSID? 

No. Assigning QoS profile is setting a max QoS ceiling (DSCP in CAPWAP or UP value in WiFi frames) for that SSID. Typically leave it to Platinum if it is corporate SSID which will allow you to set QoS value for Voice, Video, Best Effort and Background in that SSID

In my case, there is no contention in wired media, but I need solution to prioritize traffic from AP to some clients  only over wireless media. Then, when there will be much clients in the same area connected to the same AP,  I need priority over the air for all traffic goes to this specific client.

In wireless, you have 4 different traffic classes (Voice, Video, Best Effort & Background). Traffic classification is based on those 4 wireless access categories. If SSID is 802.1X, then you can assign a QoS profile to that client using AAA override (like QoS Platinum).

I do not think even with that you can prioritize downstream traffic to that client always get the highest priority, as that traffic will still mark based on the traffic coming from the wired side and how its DSCP mark in their IP packets.

HTH

Rasika

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[patrashov88]

Hi Rasika!

Thanks a lot for your reply.

What does it mean "Max QoS ceiling"? Is there difference in AIFs and backoff timers ,for example for voice traffic in Platinum and BE profiles?

AIFS and random backoff values for VOICE traffic (market as EF in wired media) in different profiles would be different?

I hope you'll help me to to clear up this :)

Thank you so much

[Rasika Nayanajith]

Hi 

"What does it mean "Max QoS ceiling"? Is there difference in AIFs and backoff timers ,for example for voice traffic in Platinum and BE profiles?"

Below a video from Jerome Henry should give some idea what we mean max qos ceiling or cap DSCP value.

Changes between AireOS 7.0 and 8.0

"AIFS and random backoff values for VOICE traffic (market as EF in wired media) in different profiles would be different?"

Depend on how you configure QoS on WLC connected ports, WLC itself that wired EF traffic QoS parameters can change at the AP before going through over the air.

Trusting DSCP is the way to go nowadays. In recent codes, we pretty much trust the inner DSCP value of the packet and simply copy it to the outer CAPWAP header. So we will maintain end to end DSCP rather rewrites UP -> DSCP and vise versa.

Pls watch below CLUS session for latest detail about wireless QoS

https://www.ciscolive.com/global/on-demand-library.html?search.event=ciscoliveus2020&search=wireless%20qos#/session/1573153552984001J0xw

HTH

Rasika

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