jitter-codec

Function

The jitter-codec command specifies a code type for a UDP voice jitter test instance.

The undo jitter-codec command deletes a code type configured for a UDP voice jitter test instance.

By default, a UDP jitter test instance is not a simulated voice test instance.

Format

jitter-codec { g711a | g711u | g729a }

undo jitter-codec

Parameters

Parameter	Description	Value
g711a	Sets the code type of a UDP voice jitter test instance to g711alaw. In G.711 a-law, the transmission rate is 64 kbit/s.	-
g711u	Sets the code type of a UDP voice jitter test instance to g711ulaw. In G.711 muHmm-law, the transmission rate is 64 kbit/s.	-
g729a	Sets the code type of a UDP voice jitter test instance to g729a. In G.729A, the transmission rate is 8 kbit/s.	-

Parameter

Description

Value

g711a

Sets the code type of a UDP voice jitter test instance to g711alaw. In G.711 a-law, the transmission rate is 64 kbit/s.

g711u

Sets the code type of a UDP voice jitter test instance to g711ulaw. In G.711 muHmm-law, the transmission rate is 64 kbit/s.

g729a

Sets the code type of a UDP voice jitter test instance to g729a. In G.729A, the transmission rate is 8 kbit/s.

Views

NQA view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
sla	write

Usage Guidelines

Usage Scenario

When a UDP jitter test instance is used to monitor VoIP services, the jitter-codec command can be used to specify the codec types used for conversion between simulated voice signals and digital signals. You can specify various code types based on actual code types in VoIP applications.

The three code types of g711a, g711u, and g729a are implemented differently in jitter test instances.

The differences in implementing code types are as follow.

g711a: the data length is 172 bytes, the sent packets number is 1000 and the packet transmission rate is 20 ms.
gu11a: the data length is 172 bytes, the sent packets number is 1000 and the packet transmission rate is 20 ms.
g729a: the data length is 32 bytes, the sent packets number is 1000 and the packet transmission rate is 20 ms.
After configuring the code types, you can run the adv-factor command to set the advantage factor for the simulated voice test calculation so that the UDP jitter test instance can be performed by simulating actual voice packets.
Running the jitter-codec and adv-factor commands to configure UDP jitter test instances helps monitor VoIP networks and analyze service traffic.

Prerequisites

The jitter-codec command is applicable only to UDP jitter test instances.
Before a UDP jitter test instance starts, ensure that the nqa-server udpecho command is used on the peer device to respond to the UDP jitter tests.

Configuration Impact

If no code type is specified for a UDP jitter test instance, the UDP jitter test instance is not a simulated voice test instance by default. In this case, the UDP jitter test instance is used for testing jitter of common services.
If a code type has been specified, running the jitter-codec command again overrides the previous configuration.
If the code type of a test instance is changed using the jitter-codec command, the previously configured advantage factor becomes invalid, and a new advantage factor needs to be set.

Precautions

If parameters need to be changed during the running of the test instance, the system prompts you whether to terminate the test instance. Press "Y" or "N" as required.

If you press "Y", the test instance is terminated and parameters changed. The settings take effect after being committed. To restart the test instance, run the start command.
If you press "N", the test instance keeps running, and the parameters fail to be modified.

Example

# Set the code type of a UDP voice jitter test instance to g711a.

<HUAWEI> system-view
[~HUAWEI] nqa test-instance admin jitter
[*HUAWEI-nqa-admin-Jitter] test-type jitter
[*HUAWEI-nqa-admin-Jitter] jitter-codec g711a