Cisco 7911G - IP Phone VoIP User Manual

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Cisco Unified IP Phone 7906G and 7911G for Cisco Unified Communications Manager 6.0
OL11954-01
Chapter 9 Troubleshooting and Maintenance
Monitoring the Voice Quality of Calls
Note • CVTQ does not support wideband (7 kHz) speech codecs, as ITU has not
defined the extension of the technique to wideband. Therefore, MOS scores
that correspond to G.711 performance are reported for G.722 calls to allow
basic quality monitoring, rather than not reporting an MOS score.
• Reporting G.711-scale MOS scores for wideband calls through the use of
CVTQ allows basic quality classifications to be indicated as good/normal or
bad/abnormal. Calls with high scores (approximately 4.5) indicate high
quality/low packet loss, and lower scores (approximately 3.5) indicate low
quality/high packet loss.
• Unlike MOS, the Conceal Ratio and Concealed Seconds metrics remain valid
and useful for both wideband and narrowband calls.
A Conceal Ratio of zero indicates that the IP network is delivering frames and
packets on time with no loss.
Troubleshooting Tips
When you observe significant and persistent changes to metrics, use Table 9-4 for
general troubleshooting information:

Cisco 7911G - IP Phone VoIP Specifications

General

Brand	Cisco
Model	7911G - IP Phone VoIP
Category	IP Phone
Language	English