1. A computer-implemented method for classifying network traffic comprising: finding a list of pairs ((a 1 , p 1 ),. .. , (a n , p n )) as a high-level policy, where a i is an application name and a corresponding p i is a priority of the application a i ; mapping the application a i to an IP address and a port number by finding a list of triples ((IPa 1 , pa 1 , in 1 ),. .. , (IPa n , pa, in n )) of low-level objects, where IPa i is a range of IP address associated with the application a i , pa i is a range of port numbers associated with the application a i , and in i is an indicator associated with the application a i ; and obtaining a low-level policy as (((IPa 1 , pa 1 , in 1 ), p 1 ),. .. , ((IPa n , pa, in n ), p n )) from the mapping and the high-level policy, where IPa i is a range of IP address associated with the application a i , pa i is a range of port numbers associated with the application a i , in i is an indicator associated with the application a i , and p i is a priority of the application a i , wherein a computing system including a processor and a memory device connected to the processor performs the finding the list of pairs ((a 1 , p 1 ),. .. , (a n , p n )), the mapping and the obtaining.