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Cisco Unified IP Phone 7960G/7940G Administration Guide for Cisco Unified Communications Manager 7.0 (SCCP)
OL-15498-01
Chapter 8 Troubleshooting and Maintenance
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 7960G/7940G. This tool is installed as part of the
Cisco
Unified Communications Manager installation.
You can configure users’ Cisco Unified IP Phone with QRT so they can report problems with phone
calls. Users can report issues by using the Cisco
Unified IP Phone softkey labeled QRT. The QRT
softkey is available only when the Cisco
Unified IP Phone is in the Connected, Connected Conference,
Connected Transfer, and/or OnHook states.
When users press the QRT softkey on their IP phone, they are presented with a list of problem
categories. Users can then choose the appropriate problem category, and their 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, 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, 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.
• 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.
MOS LQK scores are produced by a Cisco proprietary algorithm that is an implementation of
P.VTQ, an ITU provisional standard.
Note 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.
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 phones, refer to the “Phone Features”
section in the “Cisco
Unified IP Phone” chapter in 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 the
“Call Statistics Screen” section on page 6-10) or remotely by using Streaming Statistics (see
Chapter 7, “Monitoring the Cisco Unified IP Phone Remotely”).