“œWhat comes after Petabyte?” was my question to Arielle Sumits, our lead researcher on the IP Traffic Study a few years ago, when we started the effort a few years ago. Even with a wide variety of very regional and granular market forecasts on topics such as”VoIP subscription growth in Western Europe” and”IPTV subscriber forecasts for AsiaPacific,” we didn’t have visibility on what these all mean to the network as a whole. And having a global focus with a global customer base, we needed a global view. Since the market didn’t offer one, we set off to create one (and from Arielle’s standpoint, she likely did it to cease the never ending questioning from me along the lines of”But what does this all mean?” Depending on my level of caffeine consumption, my questioning can often be a far too fast and quite annoying- as my wife, Annie, can firmly attest).So in a quest to silence my questioning, Arielle went about a very extensive modeling effort, piecing together all of the more granular third party forecasts of subscription forecasts from analyst firms, such as (in alphabetical order) ABI, Dell’Oro, Gartner, IDC, Informa, Kagan, MRG, Ovum, Pyramid Research, ScreenDigest, Synergy Research, Telegeography and Yankee Group. She then factored in usage data and assumptions such as average amount of time a subscriber watches TV a day, if they have high definition, how much of their viewing does that entail, if they have a PVR, how much does that affect the streaming of video to the home even it the content is never viewed, etc. Finally, the model was worked back with Cisco engineers to determine the total sum of the impact of on the network. The result we reached (and by we, I mean Arielle) was a sizable figure- one that was in excess of 1000 petabytes, which then caused me to ask my infamous”What comes after Petabyte?” question. The answer, courtesy of Wikipedia, was”Exabyte,” hence the”Exabyte era” was born.Now, in its sixth iteration, our global IP Traffic Growth study is forecasting 29 exabytes of IP Traffic per month or nearly 350 exabytes per year by 2011, only three years from now. While that seems very aggressive to some, our CEO John Chambers has pointed out that, in this fast-moving industry, often seemingly aggressive forecasts can eventually prove to be conservative. This may very well be the case here, not just because we (and yes, I mean Arielle) intentionally based the forecasts on the lower end range of usage assumptions to maintain credibility of the project as research instead of marketing, but also because the growth of the applications and the rapid adoption of them by empowered consumers. For example, once my father began receiving high-definition television (a day that will always be cherished by him), he now does all that can to watch nothing but high-definition content, which takes up far, far more bandwidth than standard definition. And even at Cisco, when we (and by”we,” I really mean our incredible IT shop) launched its large deployment of TelePresence sites in our offices around the world (at my last count we were over 175 and reducing our travel expenditures by 20%, not to mention carbon emission reduction), our internal traffic grew not by 42% year over year but in the hundreds of percent. So with nearly 350 exabytes forecast for 2011, I am faced with an interesting question as the seventh round of our study commences and the time frame is extended a bit further:What comes after exabyte?