Is there any one has idea about what is "clean pipe" ? what exactly upstream providers do using this term " clean pipe"?
Call it "managed DDOS protection" .. sort of like the SaS model, but for networking. Simple ASCII artwork : Internet -> ISP (big pipe) -> DDOS gear -> (your circuit) -> you. In short, instead of paying for a (n*)gbps circuit and buying your own DDOS prevention gear, you buy $n worth of bandwidth that has somebody actively managing the DDOS protection. Prolexic is one of the bigger players in this market (www.prolexic.com). No, it's not cheap. But neither are circuits of sufficient capacity to absorb a 100k botnet type of DDOS and the accompanying RTBH gear (Arbor, et.al.). Cheers, Michael Holstein Cleveland State University