Network Speed Test

Feature Overview

ZEGO provides network speed test functionality, which can detect uplink and downlink network speeds before users publish/play streams, to judge what bitrate of audio/video streams is suitable for publishing/playing under current network environment.

When uplink speed test results show high packet loss rate, it is recommended to use methods such as lowering resolution or lowering frame rate to reduce publishing bitrate, ensuring normal publishing; when downlink speed test results show high packet loss rate, it is recommended to use the layered video coding function provided by the SDK to play low bitrate streams, ensuring normal playing.

When the following situations occur in developer's business, ZEGO recommends using the SDK's network speed test function:

• In call scenarios, network quality assessment needs to be performed.

• In education scenarios, pre-class network detection needs to be performed.

• In live streaming scenarios, network connection speed testing needs to be performed.

The basic principle of network speed test is shown in the following figure:

Usage Steps

1 Listen to Speed Test Callbacks

Before starting the speed test, you can first set speed test related callbacks.

• Under normal speed test circumstances, when network speed quality updates, the onNetworkSpeedTestQualityUpdate callback will be triggered.
• When an error occurs during the speed test, the onNetworkSpeedTestError callback will be triggered.

// Network speed test quality callback
// Please note, do not call any SDK interfaces in the SDK callback thread, you need to manually switch to another thread, otherwise a deadlock will occur
virtual void onNetworkSpeedTestQualityUpdate(const ZegoNetworkSpeedTestQuality& quality, ZegoNetworkSpeedTestType type)
{
    printf("onNetworkSpeedTestQualityUpdate rtt=%d packetLostRate=%f connectCost=%d type=%d", quality.rtt, quality.packetLostRate, quality.connectCost, type);
}

// Network speed test error callback
virtual void onNetworkSpeedTestError(int errorCode, ZegoNetworkSpeedTestType type)
{
    printf("onNetworkSpeedTestError errorCode=%d type=%d", errorCode, type);
}

// Network speed test quality callback
// Please note, do not call any SDK interfaces in the SDK callback thread, you need to manually switch to another thread, otherwise a deadlock will occur
virtual void onNetworkSpeedTestQualityUpdate(const ZegoNetworkSpeedTestQuality& quality, ZegoNetworkSpeedTestType type)
{
    printf("onNetworkSpeedTestQualityUpdate rtt=%d packetLostRate=%f connectCost=%d type=%d", quality.rtt, quality.packetLostRate, quality.connectCost, type);
}

// Network speed test error callback
virtual void onNetworkSpeedTestError(int errorCode, ZegoNetworkSpeedTestType type)
{
    printf("onNetworkSpeedTestError errorCode=%d type=%d", errorCode, type);
}

2 Start Speed Test

Create an instance of ZegoNetworkSpeedTestConfig network speed test configuration, set whether to perform uplink and downlink speed tests and expected bitrate according to the actual situation, and call the startNetworkSpeedTest interface to start network speed test.

ZegoNetworkSpeedTestConfig config;

// Perform uplink speed test, specify expected publishing bitrate
config.testUplink = true;
config.expectedUplinkBitrate = videoConfig.bitrate;

// Perform downlink speed test, specify expected playing bitrate
config.testDownlink = true;
config.expectedDownlinkBitrate = videoConfig.bitrate;

// Start speed test
engine->startNetworkSpeedTest(config);

ZegoNetworkSpeedTestConfig config;

// Perform uplink speed test, specify expected publishing bitrate
config.testUplink = true;
config.expectedUplinkBitrate = videoConfig.bitrate;

// Perform downlink speed test, specify expected playing bitrate
config.testDownlink = true;
config.expectedDownlinkBitrate = videoConfig.bitrate;

// Start speed test
engine->startNetworkSpeedTest(config);

Speed test results will be returned in the network speed test quality ZegoNetworkSpeedTestQuality in onNetworkSpeedTestQualityUpdate. By analyzing each parameter value, you can know whether the current network quality is good.

The parameters in ZegoNetworkSpeedTestQuality are as follows:

3 Stop Speed Test

Call the stopNetworkSpeedTest interface to stop network speed test.

After stopping the speed test, you will no longer receive onNetworkSpeedTestQualityUpdate or onNetworkSpeedTestError callbacks.

engine->stopNetworkSpeedTest();

engine->stopNetworkSpeedTest();