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Isaac
Keslassy, Shang-Tse Chuang, Kyoungsik Yu, David Miller, Mark Horowitz,
Olav Solgaard, and Nick McKeown, "Scaling internet routers using
optics," Proceedings of Sigcomm 2003, Karlsruhe, Germany, August 25-29
(ACM, New York, 2003), pp. 189 - 200 Routers built around a
single-stage crossbar and a centralized scheduler do not scale, and (in
practice) do not provide the throughput guarantees that network
operators need to make efficient use of their expensive long-haul links.
In this paper we consider how optics can be used to scale capacityand
reduce power in a router. We start with the promising load-balanced
switch architecture proposed by C-S. Chang. This approach eliminates the
scheduler, is scalable, and guarantees 100% throughput for a broad class
of traffic. But several problems need to be solved to make this
architecture practical: (1) Packets can be mis-sequenced, (2)
Pathological periodic traffic patterns can make throughput
arbitrarilysmall, (3) The architecture requires a rapidly configuring
switch fabric, and (4) It does not work when linecards are missing or
have failed. In this paper we solve each problem in turn, and describe
new architectures that include our solutions. We motivate our work
bydesigning a 100Tb/s packet-switched router arranged as 640 linecards,
each operating at 160Gb/s. We describe two different implementations
based on technologyavailable within the next three years.
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