DATE: Thursday, February 26, 2015
TIME: 12:00 pm - 1:00 pm
PLACE: RMCIC 4th Floor Panther Hollow Room

SPEAKER: Jun (Jim) Xu, GA Tech

TITLE: Sprinklers: a Randomized Variable-Size Striping Approach to Reordering-Free Load-Balanced Switching

Internet traffic continues to grow exponentially, calling for switches that can scale well in both size and speed. While load-balanced switches can achieve such scalability, they suffer from a fundamental packet reordering problem. Existing proposals either suffer from poor worst-case packet delays or require sophisticated matching mechanisms. In this work, we propose a new family of stable load-balanced switches called "Sprinklers" that has comparable implementation cost and performance as the baseline load-balanced switch, but yet can guarantee packet ordering. The main idea is to force all packets within the same virtual output queue (VOQ) to traverse the same "fat path" through the switch, so that packet reordering cannot occur. At the core of Sprinklers are two key innovations: a randomized way to determine the "fat path" for each VOQ, and a way to determine its "fatness" roughly in proportion to the rate of the VOQ. These innovations enable Sprinklers to achieve near-perfect load-balancing under arbitrary admissible traffic. Proving this property rigorously using novel worst-case large deviation techniques is another key contribution of this work.

Jun (Jim) Xu is a Professor in the School of Computer Science at Georgia Institute of Technology. A major thrust of his research lies in "Network Algorithmics", the science of designing high-speed Internet routers, firewalls, and measurement devices. He received ACM Sigmetrics 2004 Best Student Paper Award, and has been an ACM Distinguished Scientist since 2010.

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