Video conferencing problem on wireless through microsoft office communicator

[vinodk_gupta]

Hi,

We are having WLC 4402 with 30 AP connected. We are using QOS in wlc is Gold (Video). we are facing in video conferencing through Microsoft Office communicator (OCS) on wireless.

Problem Description: Picture frames are getting distorted  & sometimes Video gets loss completely. when signal strength are in very good condition on that time.

Observations:

It has been observed during Video conferencing through OCS that utilization of Ethernet Port of that AP was around 400-500 Kbps & on same time we ping the Local ip address of that local AP, latency was 1000 ms to 2000 ms  & sometimes packet gets loss.

As per standard, OCS is required 384 Kbps for video conferencing.

I am not understand what extra setting needs to be done to fix this issue.

Please help us to fix this issue.

[Nicolas Darchis]

Hi Vinod,

I think you're looking at the problem from a wrong perspective.

Is the wireless medium busy ? Is your video traffic QoS tagged by the application ? Do you trust QoS tagging on the whole network ?

Is the video multicast ? If multicast, then be aware that a multicast over wireless is like a broadcast and a killer in terms of performance. You should then check the DirectStream feature on WLC 7.0 which unicasts to every wireless clients the stream.

Nicolas

[vinodk_gupta]

yes , I want to fix this issue. Our AP is cisco 1131 & WLC product version is 4.2.205.0.

My wireless was not busy at the time of problem because when I make vedio call, at that time utilization of Ethernet port of the wireless AP was 400 to 500 Kbps which is the very normal utilization, so we can't say that wireless is busy.

Application is not tagging any QOS, We are using Gold (Video) QOS in WLC.

Please help us to how to fix this issue.

[Stephen Rodriguez]

First : Becuase the port usage was normal, does not mean that the RF wasn't busy.  To know if the RF is busy, you need to look at the %busy for that channel.

Second:  If the application does not set a QoS tag, then that is an issue as well.  From the AP, we mark the outer header with the tag we get from the client for traffic destined to the Distribution System.  From teh WLC we can inject the 802.1p tag.  But for video/voice you need end to end QoS, so the client needs to set a tag as well.