22
Configuring the voice operation
CAUTION:
To ensure successful voice operations and avoid affecting existing services, do not perform the operations
on well-known ports from 1 to 1023.
The voice operation measures VoIP network performance.
The voice operation works as follows:
1.
The NQA client sends voice packets at sending intervals to the destination device (NQA server).
The voice packets are of one of the following codec types:
{
G.711 A-law.
{
G.711
μ
-law.
{
G.729 A-law.
2.
The destination device takes a time stamp to each voice packet it receives and sends it back to the
source.
3.
Upon receiving the packet, the source device calculates the jitter and one-way delay based on the
time stamp.
The following parameters that reflect VoIP network performance can be calculated by using the metrics
gathered by the voice operation:
•
Calculated Planning Impairment Factor (ICPIF)
—Measures impairment to voice quality in a VoIP
network. It is decided by packet loss and delay. A higher value represents a lower service quality.
•
Mean Opinion Scores (MOS)
—A MOS value can be evaluated by using the ICPIF value, in the
range of 1 to 5. A higher value represents a higher service quality.
The evaluation of voice quality depends on users' tolerance for voice quality. For users with higher
tolerance for voice quality, use the
advantage-factor
command to configure the advantage factor. When
the system calculates the ICPIF value, it subtracts the advantage factor to modify ICPIF and MOS values
for voice quality evaluation.
The voice operation requires both the NQA server and the NQA client. Before you perform a voice
operation, configure a UDP listening service on the NQA server. For more information about UDP
listening service configuration, see "
The voice operation cannot repeat.
To configure the voice operation:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Create an NQA operation
and enter NQA operation
view.
nqa
entry
admin-name
operation-tag
By default, no NQA operation is
created.
3.
Specify the voice type and
enter its view.
type voice
N/A