Using The Quality Report Tool; Monitoring The Voice Quality Of Calls - Cisco 7937G - Unified IP Conference Station VoIP Phone Administration Manual

Chapter 9 Troubleshooting and Maintenance

Using the Quality Report Tool

The Quality Report Tool (QRT) is a voice quality and general problem-reporting tool for the conference
station. The QRT feature is installed as part of Cisco Unified Communications Manager.
You can configure users' conference stations with QRT. When you do so, users can report problems with
conference station calls by pressing the QRT softkey. This softkey is available only when the conference
station is in the Connected, Connected Conference, Connected Transfer, and/or OnHook states.
When a user presses the QRT softkey, a list of problem categories appears. The user selects the
appropriate problem category and this feedback is logged in an XML file. Actual information logged
depends on the user selection and whether the destination device is a conference station.
For more information about using QRT, refer to Cisco Unified Communications Manager Features and
Services Guide.

Monitoring the Voice Quality of Calls

To measure the voice quality of calls that are sent and received within the network, conference stations
use these statistical metrics that are based on concealment events. The DSP plays concealment frames
to mask frame loss in the voice packet stream.
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Concealment ratio and concealment seconds are primary measurements based on frame loss while
Note
MOS LQK scores project a "human-weighted" version of the same information on a scale from
5 (excellent) to 1 (bad) for measuring listening quality.
Listening quality scores (MOS LQK) relate to the clarity or sound of the received voice signal.
Conversational quality scores (MOS CQ such as G.107) include impairment factors, such as delay, that
degrade the natural flow of conversation.
For information about configuring voice quality metrics for conference stations, refer to Cisco Unified
Communications Manager System Guide, "Cisco Unified IP Phones" chapter, "Phone Features" section.
You can access voice quality metrics from the conference station by using the Call Statistics screen
(see the
(see
To use the metrics for monitoring voice quality, note the typical scores under normal conditions of zero
packet loss, and use the metrics as a baseline for comparison.
Cisco Unified IP Conference Station 7937G Administration Guide for Cisco Unified Communications Manager 6.0
OL-11560-01 Rev. B0
Concealment Ratio metrics—Show the ratio of concealment frames over total speech frames. An
interval conceal ratio is calculated every 3 seconds.
Concealed Second metrics—Show the number of seconds in which the DSP plays concealment
frames due to lost frames. A severely "concealed second" is a second in which the DSP plays more
than five percent concealment frames.
MOS-LQK metrics—Use a numeric score to estimate the relative voice listening quality. The
conference station calculates the mean opinion score (MOS) for listening quality (LQK) based
audible concealment events due to frame loss in the preceding 8 seconds, and includes perceptual
weighting factors such as codec type and frame size.
MOS LQK scores are produced by a Cisco proprietary algorithm that is an implementation of
P.VTQ, an ITU provisional standard.
"Call Statistics Screen" section on page
Chapter 8, "Monitoring the Conference Station
7-4) or remotely by using Streaming Statistics
Remotely").
Using the Quality Report Tool
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