Hello BrowserUk and all,

Thanks for your comments. As you said, the program is not hung. It is searching for a corresponding 'r' receive event for a 's' send event. Since it does not find any corresponding 'r'(or may find it well below) it looks like the program is hung.

Yes I am aware that the program is inefficient. In spite of that I wanted this particular program to work. Then use some efficient method like the method pointed by BrowserUk or use some PERL hash.

The scenario for the simulation is very simple and I thought this simulation scenario will not produce packet loss event but it did. Since there was loss of packets it resulted in 'r' events missing. This assumption about "no loss" caused the confusion about program hang.

Any how thanks for your help. I will post my program here when I implement some good algorithm for this delay calculation.