[ns] format routine in Trace.cc

[Nick Zando]

Hi everyone!
I am trying to create a new packet trace format.
In trace.cc i see:

void Trace::format(int tt, int s, int d, Packet* p) {

bla bla


}

I want to how does it set the right 'int tt' (kind of packet input, output,
dropped ..)

I almost finished with my new trace format but i can't set up the right 'tt'
when i debug it with gdb i can't get the right code there!