UDP Socket returns part of packet

Question

Info:Im working on a VOIP application.

Im using the C# Socket class and initalize it as a UDP socket.

My code for receiving:

if(socket.Poll(-1,SelectMode.SelectRead)){
    if(!socket.Connected){
        return;
    }
    Console.WriteLine(" AVAIL:"+socket.Available);
    int count = socket.ReceiveFrom (data, ref endpoint);
    Console.WriteLine("LENGTH:"+count);
    receivedEvent.Reuse (socket, data, count, (IPEndPoint)endpoint);
    receivedFunction (receivedEvent);
}

My code for sending:

int cnt = socket.SendTo (data, length, SocketFlags.None, ep);
if (cnt != length) {
   //LOG STUFF
}
if (sendEvent != null) {
    sendEvent (cnt);
}

ERROR: I get unexpected data from my udp socket, meaning im sending ~100 bytes of data but I only receive 31. Which is just wrong => I thought UDP will always give me all or nothing. Am I wrong ?

So my question is, shouldn't UDP be reliable in sense of packets ? Like I only should get valid or none packets ?

Another problem I seem to have (not sure if it is connected to my current issue?), after ~30 minutes my socket only returns 10 as count of data read from socket.

Answer 1

So my question is, shouldn't UDP be reliable in sense of packets ? Like I only should get valid or none packets ?

no unless you use UDP checksums, do you use raw sockets ?

ERROR: I get unexpected data from my udp socket, meaning im sending ~100 bytes of data but I only receive 31. Which is just wrong => I thought UDP will always give me all or nothing. Am I wrong ?

Did you deactivate the IP fragmentation ? https://msdn.microsoft.com/en-us/library/system.net.sockets.udpclient.dontfragment%28v=vs.110%29.aspx