3Com 4500G Family Configuration Manual page 1116

interval for the source to send these two successive packets, and thus the network status can be
analyzed.
The voice parameter values that indicate VoIP network status can also be calculated in a voice test,
including:
Calculated Planning Impairment Factor (ICPIF): Measures attenuation of voice data in a network,
depending on packet loss and delay. A higher value represents a lower network quality.
Mean Opinion Scores (MOS): Measures quality of a VoIP network. A MOS value can be evaluated
by using the ICPIF value, in the range 1 to 15. A higher value represents a higher quality of a VoIP
network.
The evaluation of voice quality depends on users' tolerance to voice quality, and this factor should be
taken into consideration. For users with higher tolerance to voice quality, you can use the
advantage-factor command to configure the advantage factor. When the system calculates the ICPIF
value, this advantage factor is subtracted to modify ICPIF and MOS values and thus both the objective
and subjective factors are considered when you evaluate the voice quality.
Configuration prerequisites
A voice test requires cooperation between the NQA server and the NQA client. Before a voice test,
make sure that the UDP listening function is configured on the NQA server. For the configuration of UDP
listening function, see
Configuring a voice test
Follow these steps to configure a voice test:
To do...
Enter system view
Enter NQA test group view
Configure the test type as voice
and enter test type view
Configure the destination
address for a test operation
Configure the destination port
for a test operation
Configure the codec type
Configuring the NQA Server.
Use the command...
system-view
nqa entry admin-name
operation-tag
type voice
destination ip ip-address
destination port port-number
codec-type { g711a | g711u |
g729a }
1-16
Remarks
—
—
Required
Required
By default, no destination IP
address is configured for a test
operation.
The destination IP address
must be consistent with that of
the existing listening service on
the NQA server.
Required
By default, no destination port
number is configured for a test
operation.
The destination port must be
consistent with that of the
existing listening service on the
NQA server.
Optional
By default, the codec type is
G.711 A-law.