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An engineer on Cisco’s data center team, Sundar Iyer, was recently recognized by Technology Review Magazine as an outstanding innovator under the age of 35 for his work on scaling router performance, a topic he first began exploring while an doctoral student at Stanford University. So what problem does Sundar’s work address? With the growth in real-time applications such as voice, video, distributed computing and gaming, there’s a growing expectation from end users that their experiences with these applications will be high quality and high performing (e.g., high definition images, great sound quality, no lag in conversations). Yet, if the memory on a router (which is used to temporarily store the video, voice and other data that is being transmitted) cannot support the speeds required to provide these quality voice/video experiences, then we cannot scale the performance of a router beyond 10-40 Gb/s, and the router performance becomes very unpredictable. For example, on a 40Gb/s link a stream of video information can arrive approximately every 10 nano-seconds (this is roughly a million times faster than the fastest human reaction time), and commodity memory cannot be accessed at such fast speeds. For example, imagine the difference between police dispatcher A who’s juggling calls for many small robberies and police dispatcher B who has one call come in on a large bank heist. Clearly, police dispatcher B will be able to give the most accurate time when the cops will arrive. Similarly if one cannot predict when one’s voice or video conferencing information gets dispatched by a router, the performance of these real-time applications will suffer. For example, the quality of a conversation degrades and becomes formal and stilted when the voice delay experienced, is more than 150 milli-seconds.It does not appear that this problem will go away anytime soon; commodity memory is built for use in computers so that they can store more data, rather than be accessed at very high speeds. And as networking speeds increase this problem will become progressively worse.Sundar’s work has allowed fast routers to overcome this memory performance problem using commodity memory. As a consequence the router can provide a high-level of guarantee on the performance of end-user applications. For the next generation of Internet applications (such as an orchestra whose musicians are in remote locations, or a doctor who performs surgery remotely using robotic sensors) this is of paramount importance. Expanding more upon innovation in the area of network memory technology that was recently recognized by Technology Magazine (published by MIT), here are a few examples of how this work impacts us: 1. Cnn.com [link: http://edition.cnn.com/2008/TECH/08/18/cyber.warfare/?imw=Y&iref=mpstoryemail] had an article earlier this week, on the threat of cyber attacks. While most attacks have been focused on computers, servers and router control infrastructure, router hardware is not immune from them — memory and interconnect (I/O) performance gaps can be exploited by a coordinated set of adversaries who may send packets in a specific order or of a specific type for which the hardware is inefficient. As an example, assume that an adversary can predict that a particular segment of memory will be used by the router, based on a specific pattern. The pattern can be repeated multiple times, causing the memory resource to be overwhelmed over time. Other similar inefficiencies may be exploited to further degrade router performance. As an analogy, imagine a large retailer flooded with customers who clogged up customer billing counters and purchased trivial items worth less than a few cents each. This would overwhelm the billing personnel and their systems. While this is hard to do in reality, on the Internet such performance attacks are easier to orchestrate. Network memory technology makes the memory and I/O 100% efficient, and provides a robust protection against cyber attacks, which exploit such inefficiencies. 2. Ikea, the Swedish furniture retailer, is successful in shipping and delivering furniture (or varying sizes) by packing them efficiently. Customers can assemble them later when they finally reach their home premises. Network memory technology performs a similar function on packets, by packing and unpacking them as required. The advantage of efficiently transferring packets is that a router can be built with a smaller number of components and interfaces. Another advantage is power, which has become the number one issue in data centers (also see a related blog posting on power on Aug 12th,”Green as a Journey not a Destination”). If packets are efficiently transferred, the worst case power consumed is reduced. Since it can easily take up to 2 watts of power to cool every watt of power consumed (due to potential cooling inefficiencies), this results in additional savings for the data center. Also the capacity that a router can support (for a given area) can be increased because the components and chips used to build the router are smaller and more efficient.

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