I am building a UDP-based audio streaming system and face a weird behavior with two different Android devices, that I do not understand at all.
I have a server broadcasting UDP packets on my local WiFi to 192.168.178.255. The Android app listens to these broadcasts using a DatagramSocket and receives the packets just fine. A MulticastLock has been acquired, but the app stays in the foreground, so this shouldn't matter.
However, after a seemingly random amount of time (around a few minutes) the app stops receiving the broadcasts. Weirdly enough, this does not only affect my own app, but also any third-party tools which can listen to UDP broadcasts. UDP packets addressed specifically to the device are still received. The device will no longer receive any broadcasts until I disable and re-enable the wifi connection.
What's even more weird: The test packets I send have a sequence number, so I can keep track of the last packet the device has received. I am running this test on two different devices (a Huawai FIG-LX1 phone and a Fire-Tablet) and the devices stop receiving packets at EXACTLY the same packet. I am looking at the network traffic on Wireshark and I can see nothing special about this packet or anything happening on the network.
Any ideas what may be killing broadcast reception on two completely different devices in this way?
Unfortunately neither of the devices are rooted, so I cannot run a network analyzer directly on the device, to determine if -for example- the router might not be forwarding the packets anymore.