Microsoft Lync 2010 and Cisco APs

Answered Question
Mar 2nd, 2012

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.

I have this problem too.
0 votes
Correct Answer by airframes about 2 years 1 month ago

Osita,

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:

http://revolutionwifi.blogspot.com/2011/09/microsoft-lync-qos.html

Justin

Correct Answer by airframes about 2 years 1 month ago

Osita,

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:

http://www.youtube.com/watch?v=44t-0JYEwkA&list=UUm3YBBhcJRokmAD1LaJg3hQ&index=15&feature=plcp

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.

Justin

  • 1
  • 2
  • 3
  • 4
  • 5
Average Rating: 5 (2 ratings)
Correct Answer
airframes Wed, 03/07/2012 - 19:05

Osita,

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:

http://www.youtube.com/watch?v=44t-0JYEwkA&list=UUm3YBBhcJRokmAD1LaJg3hQ&index=15&feature=plcp

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.

Justin

grabonlee Thu, 03/08/2012 - 01:22

Thanks Justin for your input. I had earlier come across the article by Von Nagy. It's a good article, but I have my doubt about his suggestion of using DSCP code 48 instead of 46 because it maps to 802.1p tag 6 and not 5 as RSVP 46 does. If you read the voice over wireless design manual by cisco, it actually mentions that WMM tag 6 maps to lEEE 802.1e tag 5. I will have a look at the video you mentioned this weekend and make a comment later. Once again many thanks.

grabonlee Fri, 03/09/2012 - 14:17

Hi Justin,

I had a look at my wireshark trace and discovered that the dscp 46 was mapped to cos 4, which is suprising as I expected to see 5. Anyway, I changed the QoS on my Laptop and it was mapped correctly to 5. On the video series on You tube which you mentioned, I must say that it was highly informative. However, I could not find the continuation to Part 3b as it was mentioned at the end of the video that there another series that dealt with QoS configuration and mapping on the switch. Do you have any idea of the link where the continuation series are?

airframes Fri, 03/09/2012 - 14:42

Osita,

Try this link for part 3-b: http://www.youtube.com/watch?v=D_Bk8b9P0gs&feature=youtube_gdata_player

I'm glad to hear you got the dscp-cos translations working correctly.

Thanks for the ratings and good luck with your project!

Justin

Sent from Cisco Technical Support iPhone App

grabonlee Fri, 03/09/2012 - 15:10

Justin,

I have already watched part 3-b. However, at the end of the video, Jeremy mentioned a continuation, but it nowhere to be found. I was wondering if it was posted under a different name.

Actions

Login or Register to take actions

This Discussion

Posted March 2, 2012 at 3:08 PM
Stats:
Replies:6 Avg. Rating:5
Views:3445 Votes:0
Shares:0
Tags: No tags.

Discussions Leaderboard