GCDAsyncUdpSocket on iOS missing multicasted datagrams

Question

I have a device on the network that is multicasting a very small file via UDP. The iOS app I am developing is responsible for reading these packets and I have chosen to use

Answer 1

If you want to view the packet on the iOS device, you can tether your iOS device to a Mac and mount the wifi adapter using shell command rvictl. You can then use wireshark, tcpdump, etc. to monitor the traffic on your 802.11 interface on your iOS device.

As far as not receiving data until 3 to 7 seconds - Most likely your device is entering into power save mode (IEEE PSM) which is an 802.11 feature that essentially puts the wireless NIC to sleep.
PSM mode can yield poor performance on devices - especially in your case where you have periodic bursts of data every 1/2 second. Your periodic ping is waking the NIC up.