Using The Quality Report Tool; Monitoring The Voice Quality Of Calls - Cisco 7931G Administration Manual

Using the Quality Report Tool

Using the Quality Report Tool
The Quality Report Tool (QRT) is a voice quality and general problem-reporting tool for the
Cisco Unified IP Phone. The QRT feature is installed as part of the Cisco Unified Communications
Manager installation.
You can configure users' Cisco Unified IP Phones with QRT. When you do so, users can report problems
with phone calls by pressing the QRT softkey. This softkey is available only when the
Cisco Unified IP Phone 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 Cisco Unified IP Phone.
For more information about using QRT, see the 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, Cisco Unified IP
Phones 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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MOS LQK scores are produced by a Cisco proprietary algorithm, the Cisco Voice Transmission Quality
(CVTQ) index. Depending on the MOS LQK version number, these scores may be compliant with the
International Telecommunications Union (ITU) standard P.564. This standard defines evaluation
methods and performance accuracy targets that predict listening quality scores based on observation of
actual network impairment.
Concealment ratio and concealment seconds are primary measurements based on frame loss while
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:
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For information about configuring voice-quality metrics for phones, see the Cisco Unified
Communications Manager System Guide,
You can access voice quality metrics from the Cisco Unified IP Phone by using the Call Statistics screen
(see
"Monitoring the Cisco Unified IP Phone
Cisco Unified IP Phone 7931G Administration Guide for Cisco Unified Communications Manager 8.0 (SCCP and SIP)
9-14
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
Cisco Unified IP Phone 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.
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.
Call Statistics Screen, page
Cisco Unified IP
7-12) or remotely by using Streaming Statistics. (See
Remotely.")
Chapter 9 Troubleshooting and Maintenance
Phones.
Chapter 8,
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