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Cisco Unified IP Phone 6921, 6941, 6945, and 6961 Administration Guide for Cisco Unified Communications Manager 8.5 (SCCP and SIP)
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Where to Go for More Troubleshooting Information
G.728/iLBC: 3.9 MOS LQK
G729A/AB: 3.7 MOS LQK
Note Cisco Voice Transmission Quality (CVTQ) does not support wideband (7 kHz) speech codecs,
because ITU has not defined the extension of the technique to wideband. Therefore, MOS LQK
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 or a low packet loss, and lower scores (approximately 3.5)
indicate low quality or a 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.
Where to Go for More Troubleshooting Information
If you have additional questions about troubleshooting the Cisco Unified IP Phones, several Cisco.com
web sites can provide you with more tips. Choose from the sites available for your access level.
Cisco Unified IP Phone Troubleshooting Resources:
http://www.cisco.com/en/US/products/hw/phones/ps379/tsd_products_support_troubleshoot_and_
alerts.html
Cisco Products and Services (Technical Support and Documentation):
http://www.cisco.com/en/US/products/ps10326/tsd_products_support_series_home.html
Cleaning the Cisco Unified IP Phone
To clean your Cisco Unified IP phone, use only a dry soft cloth to gently wipe the phone and the LCD
screen. Do not apply liquids or powders directly on the phone. As with all non-weather-proof
electronics, liquids and powders can damage the components and cause failures.