Jens Trier Rasmussen

The odd bit of information about Lync Server 2013, Lync 2010, Exchange 2013, SharePoint Server 2013, Exchange 2010 SP1, OCS 2007 R2, Exchange 2010 and OC 2007 R2

What is the basis for classifying a call as poor in Lync 2013 QoE?

What is the basis for classifying a call as poor in Lync 2013 QoE?

  • Comments 4
  • Likes

In Lync 2013 we changed how we classify poor calls in QoE. The flag is called ClassifiedPoorCall and it is now available in the MediaLine table. It is moved here, because we now support classifying poor calls for audio, video and application sharing.

The conditions we use to classify poor calls are shown in the 3 tables below. The poor call flag is set if one or more the conditions are met. Please note that a record in the MediaLine table can cover multiple media streams. The flagging occurs on the MediaLine level, so if you want to understand specifically which stream was the reason for the classification you need to look at the individual streams and use the columns in the tables below.

Column in AudioStream Table

Condition

Explanation

DegradationAvg

> 1.0

Network MOS Degradation for the whole call. This metric shows the amount the Network MOS was reduced because of jitter and packet loss

RoundTrip

> 500

Round trip time

PacketLossRate

> 0.1

The packet loss rate

JitterInterArrival

> 30

Average network jitter

RatioConcealedSamplesAvg

> 0.07

Average ratio of concealed samples generated by audio healing to typical samples

 

Column in VideoStream Table

Condition

Explanation

VideoPostFECPLR

> 0.1

The packet loss rate after forward error correction has been applied

VideoLocalFrameLossPercentageAvg

> 10

The percentage of total video frames that are lost

RecvFrameRateAverage

< 7

Average video frame rate used by the receiver

LowFrameRateCallPercent

> 10

Percentage of the call below the low frame rate threshold

VideoPacketLossRate

> 0.1

The packet loss rate

InboundVideoFrameRateAvg

< 7

The average video frame rate received during the call

OutboundVideoFrameRateAvg

< 7

The average video frame rate sent during the call

DynamicCapabilityPercent

> 10

Percentage of the call where the client experienced high CPU load when processing video

 

Column in AppSharingStream Table

Condition

Explanation

SpoiledTilePercentTotal

> 36

This value is the percentage of the content from the sharer that did not reach the viewer. Content may be discarded (or spoiled) when the sharer discards tiles from the graphics source or the ASMCU tiles discards tiles from Sharer respectively.

RDPTileProcessingLatencyAverage

> 400

Acceptable value of the average RDP tile processing latency in the AS Conferencing Server over the duration of the viewing session

RelativeOneWayAverage

> 1.75

Optimal value for the relative one-way delay between the two media endpoints involved in the application sharing. This is a single-hop latency measure

 

Comments
  • Thanks for the article, quite informative.

    With the generally adopted value of 150ms max RTT for an optimal VoIP call, isn't the >500ms roundtrip value a bit generous?

    Jens>Hi Alessio. You might be right, but for now we are sticking with 500 ms.

  • Thank you. Great to know!

Your comment has been posted.   Close
Thank you, your comment requires moderation so it may take a while to appear.   Close
Leave a Comment