Chapter 9
Measure Mode – Service Tab
DOCSIS
DSAM Help User Guide
Rev. 001
223
Delay
Total end-to-end packet delays severely degrade voice quality by
causing long delays between callers and causing echo problems. Any
packet delays less than 150 ms provide acceptable speech quality.
Delays greater than 150 ms begin to interfere with conversations and
cause noticeable degradation.
MOS
The Mean Opinion Score (MOS) Listening value is a conversion of the
Listening R-Value based on the ITU G.107 conversion formula. The
Mean Opinion Score (MOS) for listening represents a quantitative
value base solely on the local packet loss, jitter and delay measure-
ments. The value range for MOS is 0.0 to 5.0. MOS is computed using
the packet loss, jitter and delay results.
R-Value
The R-Value number represents a quantitative measurement value
based solely on the packet loss, jitter and delay measurements. The
value range for R-Value is 0 to 93. R-Value is computed using the
packet loss, jitter and delay results.
Viewing
VoIPCheck
Segmentation
Results
The VoIPCheck Segmentation test is a continuous test and displays
VoIP call statistics without MTA provisioning. During a VoIPCheck
Segmentation test packet loss, jitter, and delay or R-Value and MOS
values are displayed in a flow diagram graphic.
To view VoIP segmentation results
1
Press the
View
softkey.
2
Using the arrow keys, select
Segmentation
.
3
Press
ENTER
.
Figure 199
Measure Mode – VoIP Check Segmentation
Packet Loss
Jitter
Delay
21128026 R001 DSAM Help User Guide.book Page 223 Thursday, February 5, 2009 2:02 PM
