VoIPCheck Segmentation test (optional purchase required) is a continuous
test and displays VoIP call statistics without MTA provisioning. During
a VoIPCheck Segmentation test packetloss, jitter, and delay or R-Value
and MOS values are displayed in a flow diagram graphic. To perform the
VoIPCheck Segmentation test, press the VIEW softkey, use the arrow
keys to select VoIPCheck, press ENTER.
NOTE:
- VoIP test can only be initiated after the meter has successfully registered
with the CMTS, and the MTAs has successfully initialized.
- VoIP mode cannot be initiated if Ranging Only is configured.
- This test will not run if registration with the CMTS has failed.
Measurement Data
The VoIPCheck Segmentation display contains Packet or Quality measurement
data. The VoIPCheck Segmentation data is captured and continuously updated
during the VoIPCheck Segmentation process.
Packet loss, delay and jitter are factors that affect voice quality on
a VoIP network. Details of each parameter is provided as follows:
Packet loss
Significant packet loss degrades voice quality. Packet loss occurs when
packets are lost on a network, when packets are delayed too long, when
packets arrive out of order. Packet loss can cause reconstructed speech
to sound choppy and distorted.
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.
Jitter
Using the packet loss, jitter and delay information the quality display
provides the computed MOS and R-Value's. These values are intended to
give a quantitative assessment of a call. Details of each parameter is
provided as follows:
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 measurements. The value range for
MOS is 0.0 to 5.0.
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 100.
Softkeys
VIEW
The Limits menu allows you to directly display the Range, Register, Throughput,
Ping, Packet Loss, CMTS Loop, and Segmentation screens. To select a different
screen, press the VIEW softkey, use the arrow keys to select desired
mode, press ENTER.
Data
- Live: Displays continuous live
values of VoIP Segmentation
- Average: Displays the average
value of continuous live VoIP Segmatation
- Extreme: Displays the highest
or lowest values detected during VoIP Segmatation
- Packet Stats: Displays packet
loss, delay and jitter values
- Quality: Display's continuous
MOS and R-Value values
RESET
Select Reset to manually reset the displayed measurement data.