  This paper proposes a Scalable Internet Bandwidth Reservation Architecture
(SIBRA) as a new approach against DDoS attacks, which, until now, continue to
be a menace on today's Internet. SIBRA provides scalable inter-domain resource
allocations and botnet-size independence, an important property to realize why
previous defense approaches are insufficient. Botnet-size independence enables
two end hosts to set up communication regardless of the size of distributed
botnets in any Autonomous System in the Internet. SIBRA thus ends the arms race
between DDoS attackers and defenders. Furthermore, SIBRA is based on purely
stateless operations for reservation renewal, flow monitoring, and policing,
resulting in highly efficient router operation, which is demonstrated with a
full implementation. Finally, SIBRA supports Dynamic Interdomain Leased Lines
(DILLs), offering new business opportunities for ISPs.
