Troubleshooting Tips; Where To Go For More Troubleshooting Information - Cisco 7975G Software Manual

Where to Go for More Troubleshooting Information

Troubleshooting Tips

When you observe significant and persistent changes to metrics, use
troubleshooting information:
Table 9-5
Metric Change
MOS LQK scores decrease
significantly
MOS LQK scores decrease
significantly
Conceal Ratio and Conceal
Seconds increase significantly
Conceal Ratio is near or at zero,
but the voice quality is poor.
Voice quality metrics do not account for noise or distortion, only frame loss.
Note
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 7975G Administration Guide for Cisco Unified Communications Manager 7.0 (SCCP and SIP)
9-18
Changes to Voice Quality Metrics
Cisco Unified IP Phone Troubleshooting Resources:
http://www.cisco.com/en/US/products/hw/phones/ps379/tsd_products_
support_series_home.html
Cisco Products and Services (Technical Support and Documentation):
http://www.cisco.com/en/US/products/sw/voicesw/tsd_products_support_
category_home.html
Condition
Network impairment from packet loss or high jitter:
Average MOS LQK decreases could indicate widespread and
•
uniform impairment.
Individual MOS LQK decreases indicate bursty impairment.
•
Cross-check with Conceal Ratio and Conceal Seconds for evidence
of packet loss and jitter.
Check to see if the phone is using a different codec than
•
expected (RxType and TxType).
Check to see if the MOS LQK version changed after a firmware
•
upgrade.
Network impairment from packet loss or high jitter.
•
Noise or distortion in the audio channel such as echo or audio
•
levels.
Tandem calls that undergo multiple encode/decode such as calls
•
to a mobile network or calling card network.
Acoustic problems coming from a speakerphone, handsfree
•
mobile phone or wireless headset.
Check packet transmit (TxCnt) and packet receive (RxCnt) counters
to verify that voice packets are flowing.
Chapter 9 Troubleshooting and Maintenance
Table 9-5 for general
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