Android Question Current UDP Packets from multiple senders

[miker2069]

I wasn't sure where to post this as this really is a question for how receiving UDP packets works in B4A and B4i (and potentially B4R).

My scenario, I would like my App (B4i or B4a) to broadcast a device "discovery" request on my local lan using UDP. So I would send a broadcast string = "devices" on 192.168.1.255 port 5555 (for instance). Any device (in my case this would be Arduinos/ESP8266 based units) that would respond would be listening for UDP packets on port 5555, get the senders IP and send back. I am not worried about UDP server code on the Arduinos/ESP8266 (I've got that handled at the moment).

My question is if I have says 5 Arduinos on my local lan that receive the request and send back a response, will the B4i/B4A UDP Server side "queue up" the packets for me and I just need to process the received packets until there aren't any more? Or do I just get one packet and the other 4 are lost?

I suspect it will queue up but I want to confirm, thank you!

 

[Erel]

Messages will be queued. However you should expect some messages to be lost, especially with broadcasted messages.

Check this example: https://www.b4x.com/android/forum/threads/esp8266-udp-bmp180-simple-weather-station.70243/#content
There were many messages lost. In that example it was not important.

 

[miker2069]

Thank You Erel, that's what I thought. i was wondering about the percentage of packet loss and if could deal with it. My thinking would be to broadcast (to really gather the "awake" devices and their current IPs) and then have those devices connect back to the broadcasting app using TCP (so a TCP server model) for reliability.