Cisco 6800 Series Maintenance

You can access voice quality metrics from the Cisco IP Phone using the Call Statistics screen or remotely by
using Streaming Statistics.
Voice Quality Troubleshooting Tips
When you observe significant and persistent changes to metrics, use the following table for general
troubleshooting information.
Table 2: Changes to Voice Quality Metrics
ConditionMetric Change
Network impairment from packet loss or high jitter.Conceal Ratio and Conceal Seconds increase
significantly
• 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 cellular network
or calling card network.
• Acoustic problems coming from a speakerphone,
handsfree cellular phone or wireless headset.
Check packet transmit (TxCnt) and packet receive
(RxCnt) counters to verify that voice packets are
flowing.
Conceal Ratio is near or at zero, but the voice quality
is poor.
Network impairment from packet loss or high jitter
levels:
• Average MOS LQK decreases may indicate
widespread and uniform impairment.
• Individual MOS LQK decreases may indicate
bursty impairment.
Cross-check the conceal ratio and conceal seconds
for evidence of packet loss and jitter.
MOS LQK scores decrease significantly
• 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.
MOS LQK scores increase significantly
Voice quality metrics do not account for noise or distortion, only frame loss.
Note
Maintenance
4
Maintenance
Voice Quality Troubleshooting Tips

Cisco 6800 Series Specifications

General

Brand	Cisco
Model	6800 Series
Category	IP Phone
Language	English