H3C Technologies H3C MSR 5600 - Manual (Page 32)

19
Step Command Remarks
5. Specify the destination port of
UDP packets.
destination port port-number
By default, no destination port
number is specified.
The destination port number must be
the same as that of the listening
service on the NQA server.
6. Specify the payload size in
each UDP packet.
data-size size The default setting is 100 bytes.
7. Specify the string to be filled
in the payload of each UDP
packet.
data-fill string
The default setting is the hexadecimal
number
00010203040506070809.
8. (Optional.) Specify the source
port of UDP packets.
source port port-number
By default, no source port number is
specified.
9. (Optional.) Specify the source
IP address of UDP packets.
source ip ip-address
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 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 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.