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Google wants you (maybe)

November 29, 2007

Posted by Stephen Hardy

Here's a belated update to the last post on SFP+ optics for Google's DIY 10GbE switch. (No, I'm not going to link to it -- just scroll one item down!)

As I mentioned in the post, I shot an email to Google to ask if the stories about the existence of the switch were accurate and, if so, what they could tell me about the optics. I didn't have a lot of hope of getting a response, particularly when my query, directed at the media relations department, elicited a canned email from the Help Desk in reply.

However, lo and behold, I received an email from Google's Sonya Boralv (who is a frequently quoted Google media relations person) the very next day. Her response:

We can't share details on our infrastructure but would encourage any interested engineers to check out our job listings at We currently have job openings for hardware and software engineers with networking backgrounds that might be of interest to your readers.

So I've struck out so far on the optics story -- but I may be the gateway to your next career. 10% of your first paycheck there will do just fine as thanks.

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Google 10GbE switch optics

November 20, 2007

Posted by Stephen Hardy

As you've no doubt read elsewhere, Andrew Schmitt of Nyquist Capital broke a story on his blog (and if his blog isn't on your regular visit list, it should be) about Google building it's own 10GbE switch. (Read it here.)

Andrew and I have been going back and forth over the past couple of days about his description of the optics used in the switch, which he says are nonstandard implementations of SFP+ transceivers:

What is interesting about Google's approach is that it has eschewed traditional 10GBASE optical standards and instead adopted off-standard solutions that better suit its needs for time-to-market, power and port density, and cost. While Google makes use of the SFP+ cage format, it does not use the receive dispersion compensation (EDC) function typically associated with SFP+. Instead Google is looking to employ a combination of twinax cabling for short reach (<10m) intra-rack cabling and a motley 850nm SR-like standard. Off the shelf SR optical modules appear to work well up to 100m over without receive equalization. Ironically, Finisar (FNSR) proposed such a solution several years ago.

It sounded to me that either the assumption is that Google is using SR transceivers with 62.5-micron cabling (which indeed would be nonstandard -- and curious) or that SFP+ has gotten a bit too closely associated with LRM, to the point that SR versions might be considered nonstandard. Andrew tells me that "(t)hey are using standard pre-emph/receive EQ but not the full LRM EDC spec," so that's not the explanation.

Unfortunately, Andrew has been too busy to continue our discussion beyond that last bit of information. I have a query into Google on the subject, but while I was holding my breath and turning blue waiting for them to respond, I thought I'd throw the question out to you: What am I missing here?

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The Lightwave editorial staff uses The Lightwave Blog to share their thoughts on optical communications and whatever else might be the current topic of conversation from cubicle to cubicle. Feel free to add your own opinions.

Stephen Hardy is editorial director and associate publisher of Lightwave, which makes him responsible for the editorial aspects of the Lightwave franchise. A technology journalist since 1982, he once had his job duties described as "gets paid to tick off advertisers ".

Meghan Fuller is senior editor of Lightwave. She has degrees from Franklin & Marshall College in Lancaster, PA, and the University of Delaware and is a card-carrying member of Red Sox Nation.