Fwd: [ns] sequence number is -1, why?

[Anaking <anaking@sina.com>]

Hi, dear users,

Since there is no reply, I send it again.

I start from writing an application, for example a Poisson source.
But the sequence number (the 11th column) of that flow is always 
-1 in tracefile. 

What should I modify to solve that problem?

Thanks a lot