Introduction to Intel Ethernet Flow Director

By David Fair, Unified Networking Marketing Manager, Intel Networking Division

Certainly one of the miracles of technology is that Ethernet continues to be a fast growing technology 40 years after its initial definition.  That was May 23, 1973 when Bob Metcalf wrote his memo to his Xerox PARC managers proposing “Ethernet.”  To put things in perspective, 1973 was the year a signed ceasefire ended the Vietnam War.  The U.S. Supreme Court issued its Roe v. Wade decision. Pink Floyd released “Dark Side of the Moon.”

In New York City, Motorola made the first handheld mobile phone call (and, no, it would not fit in your pocket).  1973 was four years before the first Apple II computer became available, and eight years before the launch of the first IBM PC. In 1973, all consumer music was analog: vinyl LPs and tape.  It would be nine more years before consumer digital audio arrived in the form of the compact disc—which, ironically, has long since been eclipsed by Ethernet packets as the primary way digital audio gets to consumers.


The key reason for Ethernet’s longevity, IMHO, is its uncanny, Darwinian ability to evolve to adapt to ever-changing technology landscapes.  A tome could be written about the many technological challenges to Ethernet and its evolutionary response, but I want to focus here on just one of these: the emergence of multi-core processors in the first decade of this century.

The problem Bob Metcalf was trying to solve was how to get packets of data from computers to computers, and, of course, to Xerox laser printers.  But multi-core challenges that paradigm because Ethernet’s job as Bob defined it, is done when data gets to a computer’s processor, before it gets to the correct core in that processor waiting to consume that data.

Intel developed a technology to help address that problem, and we call it Intel® Ethernet Flow Director.  We implemented it in all of Intel’s most current 10GbE and 40GbE controllers. What Intel® Ethernet Flow Director does, in a nutshell, is establish an affinity between a flow of Ethernet traffic and the specific core in a processor waiting to consume that traffic.

I encourage you to watch a two and a half minute video explanation of how Intel® Ethernet Flow Director works.  If that, as I hope, whets your appetite to learn more about this Intel technology, we also have a white paper that delves into deeper details with an illustration of what Intel® Ethernet Flow Director does for a “network stress test” application like Memcached.  I hope you find both the video and white paper enjoyable and illuminating.

Intel, the Intel logo, and Intel Ethernet Flow Director are trademarks of Intel Corporation in the U.S. and/or other countries.

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