Configuring a voice operation – H3C Technologies H3C SecBlade LB Cards User Manual
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Step Command
Remarks
9.
Configure the source IP
address of UDP packets.
source ip ip-address
Optional.
By default, no source IP address is
specified.
The source IP address must be that of an
interface on the device and the interface
must be up. Otherwise, no UDP packets
can be sent out.
Configuring a voice operation
CAUTION:
Do not perform a voice operation to a well-known port from 1 to 1023. Otherwise, the NQA operation
might fail or the service on that port becomes unavailable.
A voice operation measures voice over IP (VoIP) network performance.
A voice operation works as follows:
1.
The NQA client sends voice packets of G.711 A-law, G.711 μ-law or G.729 A-law codec type at
a specific interval to the destination device (NQA server).
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, which you should consider.
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, so both objective and subjective factors are considered.
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 "
A voice operation cannot repeat.
To configure a voice operation:
Step Command
Remarks
1.
Enter system view.
system-view
N/A