Ns2 creates trace file which can give almost all the information we want .

Hers is the link for contents of trace file ...

http://ns2ultimate.tumblr.com/post/2496927327/post-processing-ns2-result-using-ns2-trace-trace

Now you can extract information you want by any language or script you want by accessing trace file.

you can do it by tsh trace

http://search.cpan.org/~kostas/Net-Traces-TSH-0.16/TSH.pm#Using_the_Net::Trace::TSH_trace_summary_hashes

Trace file helps you to get all the events from simulation start to end time..