Intel Research Seminar

DATE: Thursday, April 3, 2003
TIME: Noon - 1:30 pm
PLACE: Intel Seminar (417 S. Craig Street - 3rd Floor)

Ken Yocum
Duke University

Network Intermediaries for Constructing and Evaluating Scalable
Network Services

Network intermediaries commonly act as switching elements, supporting scalable and robust Internet services. Intermediaries may intercept, transform, and redirect network traffic to increase system performance or enhance system functionality. This talk will explore the role of intermediaries for the construction of cluster-based network services and large-scale network emulators. Anypoint is a new model for one-to-many communication with ensemble sites, aggregations of end nodes that appear to the external Internet as unified sites. ModelNet, a large-scale network emulator, evaluates network systems in complex Internet-like environments.

Anypoint is an extensible router architecture that performs transport switching for building scalable Internet services. Transport switching enables reliable, ordered, rate-controlled communication to the ensemble through a redirecting switch. Service routing plugins extend switches at the network edge and can inspect, transform, and redirect transport-layer flows. Anypoint is designed for emerging transports with application-level framing; it is the first routing approach to switch at the granularity of transport frames. Anypoint maintains transport guarantees between end nodes, avoiding protocol termination in the switch. Experiments comparing Anypoint to an application-layer proxy quantify CPU and memory performance benefits. A scalable NFS storage appliance illustrates the structure and design of Anypoint services.

In the second part of the talk I show how network intermediaries form the basis for large-scale network emulation. Network systems are difficult to evaluate due to their scale and the complexity of the Internet. ModelNet presents a network emulation environment, built above a scalable gigabit LAN cluster, for deploying unmodified software prototypes (and operating systems) in a configurable Internet-like environment. ModelNet emulates the network on a hop-by-hop basis, and accurately captures the effects of congestion, queuing, and cross traffic. In this context, the emulator is a cluster of intermediaries that coordinate to impose wait times on packets. This part of the talk will focus on maintaining emulation accuracy, and techniques for scaling emulation across a set of emulation nodes.

Ken Yocum is a PhD candidate in computer science at Duke University. His research focus is at the network/OS boundary. Recent work explores the role of network intermediaries for emerging frame-based transport protocols to construct Internet services. His work includes ModelNet, a tool to evaluate these large-scale network services across a scalable network emulator. Ken received his undergraduate degree in computer science from Stanford University in 1996. Ken's previous research projects include the Trapeze messaging system for Myrinet, adaptive message pipelining and other techniques for network storage systems, end-system techniques for high-speed TCP, and optimized data paths for forwarding network intermediaries.

For Further Seminar Info:
Contact Kim Kaan, 412-605-1203, or visit

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