Cisco 7911G Administration Guide - Page 247

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: OL11954-01 Cisco Unified IP Phone 7906G and 7911G for Cisco Unified Communications Manager 6.0 9-27