Configuring voice tests



Do not perform voice tests on known ports, ports from 1 to 1023. Otherwise, the NQA test might fail or the corresponding services of these ports might be unavailable.

Voice tests of an NQA test group are used to test voice over IP (VoIP) network status, and collect VoIP network parameters so that users can adjust the network.

A voice test performs the following procedure:

  1. The source (NQA client) sends voice packets of G.711 A-law, G.711 µ-law or G.729 A-law codec type at regular intervals to the destination (NQA server).

  2. The destination affixes a time stamp to each voice packet that it receives and then sends it back to the source.

  3. Upon receiving the packet, the source calculates results, such as the delay jitter and one-way delay based on the packet time stamps. The statistics reflect network performance.

Voice test result also includes the following parameters that reflect VoIP network performance:

The evaluation of voice quality depends on users' tolerance for voice quality, which should be taken into consideration. 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, this advantage factor is subtracted to modify ICPIF and MOS values, so objective and subjective factors are both considered when you evaluate voice quality.

Configuration prerequisites

To configure voice tests:




1. Enter system view.



2. Enter NQA test group view.

nqa entry admin-name operation-tag


3. Configure the test type as voice, and enter test type view.

type voice


4. Configure the destination address of voice probe packets.

destination ip ip-address

By default, no destination IP address is configured for a test operation.

The destination IP address must be the same as that of the listening service on the NQA server.

5. Configure the destination port of voice probe packets.

destination port port-number

By default, no destination port number is configured.

The destination port must be the same as that of the listening service on the NQA server.

6. Configure the codec type.

codec-type { g711a | g711u | g729a }


By default, the codec type is G.711 A-law.

7. Configure the advantage factor for calculating MOS and ICPIF values.

advantage-factor factor


By default, the advantage factor is 0.

8. Specify the source IP address of probe packets.

source ip ip-address


By default, no source IP address is specified.

The source IP address must be the IP address of a local interface. The local interface must be up. Otherwise, no probe packets can be sent out.

9. Specify the source port number of probe packets.

source port port-number


By default, no source port number is specified.

10. Configure the size of the data field in each probe packet.

data-size size


By default, the probe packet size depends on the codec type. The default packet size is 172 bytes for G.711A-law and G.711 µ-law codec type, and 32 bytes for G.729 A-law codec type.

11. Configure the string to be filled in the data field of each probe packet.

data-fill string


By default, the string is the hexadecimal number 00010203040506070809.

12. Configure the number of probe packets to be sent during each voice probe operation.

probe packet-number packet-number


1000 by default.

13. Configure the interval for sending probe packets during each voice probe operation.

probe packet-interval packet-interval


20 milliseconds by default.

14. Configure the interval the NQA client must wait for a response from the server before it regards the response times out.

probe packet-timeout packet-timeout


5000 milliseconds by default.

15. Configure optional parameters.

See ""