iOS Socket weird behavior

I have some code like this :

Actually my code is the modified version of SimplePing (http://developer.apple.com/library/mac/#samplecode/SimplePing/Introduction/Intro.html

The weird thing is :
- If INTERVAL is big number (Eg, 0.5s), then everything works fine. The callback is called for every packet that is sent.
- If INTERVAl is small (Eg, 0.02s), then the callback is always called for the first 50 packets. Callback is not called for all later packets.

I'm not sure but i think there's something special about this number "50". I've run this app many times and it's always the same.

Hi,

Thanks for your reply.

You can download the source code here. Currently, in main.c, the timer is fired every 1 second. Just change it to 0.2 second. You will see that : from the 49th ping, all pings are sent but there's no reply from server.