23-16interval for the source to send these two successive packets, and thus the network status can beanalyzed.The voice parameter values that indicate VoIP network status can also be calculated in a voice test,including:z 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.z Mean Opinion Scores (MOS): Measures quality of a VoIP network. A MOS value can be evaluatedby using the ICPIF value, in the range 1 to 15. A higher value represents a higher quality of a VoIPnetwork.The evaluation of voice quality depends on users’ tolerance to voice quality, and this factor should betaken into consideration. For users with higher tolerance to voice quality, you can use theadvantage-factor command to configure the advantage factor. When the system calculates the ICPIFvalue, this advantage factor is subtracted to modify ICPIF and MOS values and thus both the objectiveand subjective factors are considered when you evaluate the voice quality.Configuration prerequisitesA 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 ofUDP listening function, see Configuring the NQA Server.Configuring a voice testFollow these steps to configure a voice test:To do… Use the command… RemarksEnter system view system-view —Enter NQA test group view nqa entry admin-nameoperation-tag —Configure the test type asvoice and enter test type view type voice RequiredConfigure the destinationaddress for a test operation destination ip ip-addressRequiredBy default, no destination IPaddress is configured for a testoperation.The destination IP addressmust be consistent with that ofthe existing listening service onthe NQA server.Configure the destination portfor a test operation destination port port-numberRequiredBy default, no destination portnumber is configured for a testoperation.The destination port must beconsistent with that of theexisting listening service on theNQA server.Configure the codec type codec-type { g711a | g711u |g729a }OptionalBy default, the codec type isG.711 A-law.
