Cisco 8961 Administration Manual page 196

Status Menu
Table 10-5
Item
Avg Jitter
Max Jitter
Rcvr Discarded
Rcvr Lost Packets
Voice-Quality Metrics
MOS LQK
Avg MOS LQK
Min MOS LQK
Max MOS LQK
MOS LQK Version
Cumulative Conceal Ratio
Interval Conceal Ratio
Max Conceal Ratio
Conceal Secs
Cisco Unified IP Phone 8961, 9951, and 9971 Administration Guide for Cisco Unified Communications Manager 8.6 (SIP)
10-12
Chapter 10 Viewing Model Information, Status, and Statistics on the Cisco Unified IP Phone
Call Statistics Items for the Cisco Unified Phone (continued)
Description
Estimated average RTP packet jitter (dynamic delay that a packet
encounters when going through the network), in milliseconds, observed
since the receiving voice stream opened.
Maximum jitter, in milliseconds, observed since the receiving voice
stream opened.
Number of RTP packets in the receiving voice stream that were
discarded (bad packets, too late, and so on).
The phone discards payload type 19 comfort noise packets that
Note
are generated by Cisco Gateways, which 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 eight-second interval of the voice stream. For more
information, see the
page 12-16.
The MOS LQK score can vary based on the type of codec that
Note
the 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).
"Monitoring the Voice Quality of Calls" section on