Abstract. Present-day networks are challenged by dramatic increases in data rate demand of emerging applications. With the advancement of high speed fiber communications with per wavelength transfer rate of 100Gbps or more and free space optical links for close-in data/computing center interconnects, unscheduled high speed data transfer of "elephant" (large volume) transactions are a reality. To make full use of the technology of optics and the very high data transfer rates, new network architectures from the physical to the transport layer are needed. This talk will address new network architectures, free of constraints of previous architectures and protocols, that will make "elephant" transactions much more efficient with much less network delays. Substantial performance gains can be expected for these new networks not just because the physical layer is faster but the upper layer protocols are also much improved in performance due to radical changes in architectures.