Comms chips

Cisco Goes Inside With Silicon Photonics

Cisco Systems Inc. is applying silicon photonics not only to 100Gbit/s modules, but to its own ASICs as well. That was one of the many tech snippets Cisco discussed at its Editors Conference, an information session held Wednesday in San Jose, Calif., for the press. More than a dozen executives took the stage to talk about their domains inside Cisco, and silicon photonics was brought up by David Ward, a Cisco CTO and chief architect. In public, Ward has mostly spoken about Cisco's software-defined networking (SDN) initiatives. But given the option to pick favorite technologies to tell reporters about, he chose to deviate from SDN for a few minutes to talk about silicon photonics, which he called "absolutely the most interesting thing going on in ASIC technology today."

David Ward famously gives his talks while pacing in his socks
Optical chip-to-chip connections will definitely be a factor in Cisco's next-generation ASICs, and the company already has the technology working in the lab, Ward told Light Reading. Cisco got its silicon photonics expertise last year by acquiring Lightwire, which was aiming its silicon photonics at optical modules. Sometime this year, Cisco is expected to formally announce the CPAK format for 100Gbit/s pluggable modules, an alternative to the CFP and CFP2 standards. The more commonly mentioned aspect of silicon photonics, though, is the technology's potential in chip-to-chip interconnect. Intel Corp. is particularly interested in using silicon photonics to boost the input/output density on future chips, because lasers could do the job without pushing power consumption and heat to unreasonable levels. Ward brought up an ancillary benefit: "Because these are much smaller packages for the amount of I/O bandwidth that they have and they use much less power, we now can combine more feature logic into the chip, [rather] than just I/O logic." Cisco has a vested interest in ASIC advances, because it's staking much of its future on a continued churn-out of ASICs. Asked by Light Reading on Wednesday how much longer Cisco expects ASIC-driven equipment to be vital to networking, Senior Vice President Rob Lloyd said, "Forever." Software will be increasingly important, too, but Cisco is convinced that mobility and cloud-based applications will intensify the need for ASIC-based processing throughout the network. For more
— Craig Matsumoto, Managing Editor, Light Reading
Craig Matsumoto 3/15/2013 | 2:30:47 PM
re: Cisco Goes Inside With Silicon Photonics -áYep, I agree the router low-end will get eaten away. Cisco seems to doubt that (or, to put it another way, maybe they can't afford to believe it?) -- Lloyd's theory is that the increased processing required by cloud/mobility will drive the network edges to require something more sophisticated than x86s.

But I the opposite case is plausible too, where the edge becomes a lot of busy, dumb, task-churning processors with all the heavy-lifting software existing in a controller, or "in the cloud," if you want to say it that way.

(I'm talking about the telecom network here. I think even Cisco would agree there's a low low end -- my house, e.g. -- where an x86/Linux router will be just fine.)
soldack 3/15/2013 | 1:46:14 AM
re: Cisco Goes Inside With Silicon Photonics Cisco often buys or works with multiple companies in the same space. -áIn the InfiniBand arena they purchased TopSpin but they shortly there after resold SilverStorm/QLogic gear for awhile. -áASIC will work on the high end and if the volumes are right. -áLittle linux routers are getting better though and will eat up the low end eventually. -áIt was a little while ago that someone posted a server routing 80 gbps using all off the shelf equipment.
Craig Matsumoto 3/14/2013 | 10:44:15 PM
re: Cisco Goes Inside With Silicon Photonics -áWell... I'm not sure the startups' technologies overlapped that much. Lightwire was about silicon photonics, and CoreOptics' important pieces were other electronics that happen to relate to 100G coherent.

David Ward wasn't saying silicon photonics *are* ASICs, just that the technology is very important to ASICs, and I think he's right.-á I think chip-to-chip interconnect is what most people think about when they think silicon photonics. The technology definitely has a role with future generations of really large chips.
redface 3/14/2013 | 8:47:35 PM
re: Cisco Goes Inside With Silicon Photonics Cisco bought CoreOptics in 2010 for "highly advanced 100 Gbps technology". -áNow there is Lightwire, for the same 100G technology. -áGo figure. -áIt seems more like Cisco does not know what it is doing. -áRegardless of what Mr. David Ward says, Silicon Photonics is not ASIC. -áIt just shows how clueless Cisco is regarding components. -áAnd Cisco has had almost no success in doing component level work to speak of. -á
Craig Matsumoto 3/14/2013 | 6:17:51 PM
re: Cisco Goes Inside With Silicon Photonics -áTrue. I was surprised to hear they were already trying on-chip optics.

Of course, Cisco's forward thinking focuses on preserving the key Cisco franchises. While Rob Lloyd has a point about ASIC-driven gear, Cisco is dependent on that trend lasting "forever." I do wonder if the company is taking any steps to be ready in case the x86 revolution suddenly happens. I talked with Pankaj Patel about this a little bit yesterday, so I'm hoping to post that interview soon.
Deirdre Blake 3/14/2013 | 3:05:36 PM
re: Cisco Goes Inside With Silicon Photonics They're certainly trying to cover all the bases; nice to see some forward thinking coming from Cisco these days.
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