I don't think you will get much help from these forums. A little investigation indicates that you are probably trying to use ns2, a network simulator, to generate traffic for some purpose known only to yourself. I suggest looking for a forum that specialises in ns2 so that you are among friends who know the package. A quick bit of googling for "ns2 forum" came up with http://old.nabble.com/Network-Simula...-2-f15582.html
as an example. When you post a question you need to be very clear and comprehensive about what you are trying to do otherwise you will be greeted with silence.