This is a DOS stress tester, it is NOT DDOS
DDOS means a Distributed Denial Of Service, sending so many connections of different origins (bots) that it overwhelms any legitimate traffic each bot launching the attack exponentially ads to the attack bandwidth
DOS IS simply Denial OF Service, (Not distributed just one bot, yourself) You will use up all of your bandwidth trying to perform the attack. Since your single connection does not have enough bandwidth to bring down any fairly large site, the only thing you will do is DOS yourself offline (Overwhelm your own connection )