My company has extensively deployed Microsoft Lync Enterprise voice and this was an upgrade from OCS R2. Staff in my company have complained often of poor calls over wireless. I have resisted applying QoS for now until I understand fully how Cisco APs and WLCs implement QoS. I recently watched a video from Aruba networks comparing performance of Lync calls over its access points and Cisco access points. The Cisco setup was a 3500 AP and 5508 WLC with 7.0.116 code. There were also other bandwidth consuming applications running at the background. I must say that I was impressed at how Aruba's access point performed over Cisco access points. This is because Aruba does application specific QoS and not the traditional client or SSID QoS.
I am considering making recommendation to management to go Aruba for the upgrade of a larger subsidiary. However, before I make such a recommendation,I have 2 quetstions
1. I would like to know if Cisco has revamped its WLC code to better deal with Lync and if so, I would be grateful if I could be shown any documentation or video on how to implement QoS to improve Lync experience.
2. Also if HREAP is implemented, does the WLC still implement QoS or has this to be handled by the switch since packets are locally switched.
I currently have a mix of 5508 and 4404 WLCs with over 300 1041n APs.
One addition: Andrew VonNagy wrote an excellent analysis of Lync's QoS behavior, how it fits into wireless networks and how to think about planning network-wide QoS around it. It looks like it would be a worthwhile read as part of your Lync deployment planning:
As far as I know, Cisco has not done any optimization specifically for Lync, but as long as Lync is using standards-based tagging for the latency-sensitive parts of the application (voice and video), then you can elevate your WLAN QoS setting to the appropriate metal to allow for elevated QoS-tagged traffic on that WLAN.
Keep in mind that the controller does not actively tag upstream client traffic, so even if you have clients doing other applications on their workstations over that WLAN, that traffic will not be re-marked from best effort to a multimedia QoS level. I.e., you can have a WLAN that shares both data and voice/video in a Lync environment.
If you want to learn WLC QoS from the best (IMO), here is is Jerome Henry doing a 5-part video series explaining and implementing QoS on the WLC. It starts with Part 1, and the goes to Part 2-a, 2-b, 3-a and 3-b:
Locally switched HREAP traffic will come out into the switchport marked with the DSCP tag given to it by the application. It is up to you to configure proper end-to-end QoS on your network from there.