An important and challenging problem is that of tracing DOS/DDOS attack source. Among many IP Traceback schemes, a recent development is DGT (Directed Geographical Traceback). Though multidirectional two dimensional DGT schemes are available, in the real scenario, three dimensional, Multidirectional DGT has potential applications. The direction ratio algorithm[DRA] has the limitation of the impossibility of ensuring sufficient unused space in the packet header for the complete DRL (Direction Ratio List) especially when the length of the path is not known apriori. In this paper that limitation is overcome using DRSA(Direction Ratio Sampling Algorithm) which works well for Three dimensional, Multi-Directional, Geographical IP traceback. This approach enables the attack path reconstruction easily possible. In conclusion, DRSA is a robust scheme of attack path reconstruction in geographical traceback.