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Android: lost UDP datagram



  • Hi,

    I am facing to a strange problem with my Android device (Android 7.1.2).
    I want to send UDP Datagram to a PC via WIFI, WIFI is on and connected to the right access point.
    I send Datagram with unicast IP address, but datagram never reached the PC.
    Wenn I remove the SIM card from the Android device datagram arrives to PC!!

    Is there something special to do with android device to use QUdpSocket?


  • Qt Champions 2020

    It's normal for Android && WiFi network.



  • @kuzulis What do you mean with normal? I want to send an UDP Datagram to a device with is on the connected Wifi network.
    I send to a given IP with is in WIFI IP address range, so why it is not send on this subnet?

    This not normal


  • Qt Champions 2020

    We faced with this similar issues too. Some UDP frames were delivered, some were dropped/lost, some were deferred (delivered later, after some time). This depends on an Android device (on some devices it does work, and on some devices the frames gets dropped). We even created own 'UDP' class, but it does not help. Seems, it depends on an Android device and Android version. It was a hell for us... So, it is normal on Android (we did not win it).. :)


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