First of all, the NS-2 result is very excellent and accepted in reputed journals. Secondly, both ns-2 and ns-3 are apowerful tool for research methodology and each one has features for example ns-2 code available from many resource, while ns-3 has additional feature for new wireless network.-2 and ns-3 are a powerful tool for research methodology and each one has features for example ns-2 code available from many resource, while ns-3 has additional feature for new wireless network.