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学术报告通知
报告题目
:
All-optical Bufferless Switching Modes and Congestion Control Protocols
报告人：Chunming Qiao
（乔春明）教授, 美国
SUNY Buffalo
大学
主持人：喻松 副教授
时间:
2013
年6月20日 下午3:00-4:30
地点:
科研楼314会议室
报告内容
:
In this talk, I will first discuss two bufferless optical switching modes: optical burst switching (OBS) vs. optical flow/circuit switching (OFS/OCS), and compare the performance of these two modes for a range of workloads and network configurations. We will show how common empirical filesize distributions lead to most of the bytes being transported by a few flows, and most of the flows being very short (50% of flows only carry 3 or 4 packets in common scenarios). Since creating a lightpath in OFS/OCS takes time, and since they are very fast once created (i.e., they transport the few packets that the majority of flows have, in a very small time), the effective lightpath utilization is poor in most cases; only the few flows that are very large can make a good use of network resources in OFS/OCS. In this situation, OBS offers better network utilization even taking into account its lossy nature due to the presence of congestion-based losses and the lack of optical buffers.
We will also present a study of congestion control schemes over an OBS network and show that typical TCP congestion control protocols ---mainly AIMD--- which have been designed for buffered networks and in some cases optimized for long-fat networks (LFNs), do not perform well; Instead, simpler congestion control mechanisms like stop-and-wait perform much better, e.g., in a 3-level fat tree whose end-to-end path delay is not overly long (such as in a datacenter network).
信息光子学与光通信国家重点实验室
2013
年
6
月20
日
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报告人简介
Professor Qiao pioneered optical burst switching or OBS, and integrated cellular and Wi-Fi technologies(iCAR) around 1999 and was elevated to an IEEE Fellow for these contributions. He has published hundreds of highly cited papers with an h-index of at least 50. One of his papers has been cited over 2000 times by others. His research has been funded by about a dozen of grants from US's National Science Foundation, and a dozen of major IT and telecommunications companies including Cisco, Fujitsu Labs, Google, NEC Labs etc.. His work has resulted in several patents, and has been featured in BusinessWeeks, Wireless Europe and New Scientists.
