Ever-larger data centers are powering the cloud computing revolution, but the scale of these installations is currently limited by the ability to provide sufficient internal network connectivity. Delivering scalable packet-switched interconnects that can support the continually increasing data rates required between literally hundreds of thousands of servers is an extremely challenging problem that is only getting harder. This project leverages microsecond optical circuit-switch technology to develop a hybrid switching paradigm that spans the gap between traditional circuit switching and full-fledged packet switching, achieving a level of performance and scale not previously attainable. This will result in a hybrid switch whose optical switching capacity is orders of magnitude larger than the electrical packet switch, yet whose performance from an end-to-end perspective is largely indistinguishable from a giant (electrical) packet switch.
The research provides a quantitative baseline for hybrid network design across a wide range of present and future technologies. The project will consist of five parts: i) traffic characterization to identify the class of network traffic that a circuit switch can support as well as the partitioning of the traffic between the circuit and packet portions of the network; ii) circuit scheduling to enable the circuit switch to rapidly multiplex a set of circuits across a large set of data center traffic flows; iii) traffic conditioning to reduce the variability of traffic at the end hosts, easing the demands placed on switch scheduling; iv) a prototype hybrid network that can use an optical circuit switch that operates three orders of magnitude faster than existing solutions; and v) a trend analysis to understand the tradeoffs resulting from potential future technology advances.
The work stands to dramatically improve data center networks, significantly reducing operating costs and increasing energy efficiency. The research material will be incorporated into courses, helping to train the next generation of computer networking scientists and engineers. The PIs will also continue ongoing outreach to high school students, both through the UCSD COSMOS summer program and through talks delivered at local high schools.
