Cisco 7940 - IP Phone VoIP Administration Manual page 91

Chapter 6 Viewing Model Information, Status, Statistics, and Security Information on the Cisco Unified IP Phone
Table 6-4
Item
Avg Jtr
Max Jtr
RxDisc
RxLost
Voice Quality Metrics
MOS LQK
Avg MOS LQK
Min MOS LQK
Max MOS LQK
MOS LQK Version
Cmltve Conceal Ratio
Interval Conceal Ratio
Max Conceal Ratio
Conceal Secs
Severely Conceal Secs
Cisco Unified IP Phone 7960G/7940G Administration Guide for Cisco Unified Communications Manager 7.0 (SCCP)
OL-15498-01
Call Statistics Items (continued)
Description
Estimated average RTP packet jitter (dynamic delay that a packet
encounters when going through the network) observed since the receiving
voice stream was opened.
Maximum jitter observed since the receiving voice stream was opened.
Number of RTP packets in the receiving voice stream that have been
discarded (bad packets, too late, and so on).
The phone will discard payload type 19 comfort noise packets that
Note
are generated by Cisco Gateways, which will increment this counter.
Missing RTP packets (lost in transit).
Score that is an objective estimate of the mean opinion score (MOS) for
listening quality (LQK) that rates from 5 (excellent) to 1 (bad). This score
is based on audible concealment events due to frame loss in the preceding
8-second interval of the voice stream. For more information, see the
"Monitoring the Voice Quality of Calls" section on page
The MOS LQK score can vary based on the type of codec that the
Note
Cisco Unified IP Phone uses.
Average MOS LQK score observed for the entire voice stream.
Lowest MOS LQK score observed from start of the voice stream.
Baseline or highest MOS LQK score observed from start of the voice
stream.
These codecs provide the following maximum MOS LQK score under
normal conditions with no frame loss:
G.711 gives 4.5
•
G.729 A /AB gives 3.7
•
Version of the Cisco proprietary algorithm used to calculate MOS LQK
scores.
Total number of concealment frames divided by total number of speech
frames received from start of the voice stream.
Ratio of concealment frames to speech frames in preceding 3-second
interval of active speech. If using voice activity detection (VAD), a longer
interval might be required to accumulate 3 seconds of active speech.
Highest interval concealment ratio from start of the voice stream.
Number of seconds that have concealment events (lost frames) from the
start of the voice stream (includes severely concealed seconds).
Number of seconds that have more than 5 percent concealment events (lost
frames) from the start of the voice stream.
Call Statistics Screen
8-15.
6-11