The　distributed　denial　of　service　(DDoS)　attack　is　detrimental　to　businesses　and　individuals　as　people　are　heavily　relying　on　the　Internet.　Due　to　remarkable　profits,　crackers　favor　DDoS　as　cybersecurity　weapons　to　attack　a　victim.　Even　worse,　edge　servers　are　more　vulnerable.　Current　solutions　lack　adequate　consideration　to　the　expense　of　attackers　and　inter-defender　collaborations.　Hence,　we　revisit　the　DDoS　attack　and　defense,　clarifying　the　advantages　and　disadvantages　of　both　parties.　We　further　propose　a　joint　defense　framework　to　defeat　attackers　by　incurring　a　significant　increment　of　required　bots　and　enlarging　attack　expenses.　The　quantitative　evaluation　and　experimental　assessment　showcase　that　such　expense　can　surge　up　to　thousands　of　times.　The　skyrocket　of　expenses　leads　to　heavy　loss　to　the　cracker,　which　prevents　further　attacks.　©　2021　IEEE.