Thanks for the informative delineation of the distributed computing ecosystem. I have a few queries about the projected adaptation of cloud and fog computing worldwide.

Do you think the projection of the anticipated scale of the "Internet of Things" to the tune of 50 billion devices by 2020 is more than a little ambitious considering:

1) The adoption of IPv6 is so slow. A full twenty years after the idea was first mooted in RFC 1883, IPv6 adoption worldwide has reached just over 10%. Of these, only North America has over 25% of connected users using native IPv6.
We would need all devices to support native IPv6 in order to support this scale of IP enabled devices. So possibly we should also focus our efforts on developing products and utilities that make native IPv6 administration as automated and painless as possible. [1]

2) In order to ensure end-to-end security, practically all network elements would need to support encryption. Would low power, low cost and low memory/CPU end devices have the ability for encryption using TLS/DTLS?

3) These large number of devices would cause a lot more interference on the limited 2.4 GHz spectrum that is freely available unless more spectrum is made available in the 5GHz or even in the 28-39 GHz and higher bands (that have serious line of sight limitations).

4) While we provide the ecosystem, the end user devices as well as the cloud analytics apps are third-party. How does Cisco find a foothold in the applications space that would be the real revenue generator? This is considering that data-centers, cloud based computing and storage etc. are being heavily commoditized with the likes of Amazon, Google, Rackspace, Microsoft, Facebook etc. driving the prices of their hosted cloud services lower and lower everyday.

That being said, there is definitely a lot of scope for harnessing the power of edge devices for stratified data analytics. The Mobility Express setup, for example, could be used as a distributed computing setup. Since load balancing between APs is dependent on the physical location of APs, there would be some APs that would not have any clients attached and could not be used for load balancing due to physical distance from clients. Even so, the setup could be used to distribute RRM calculations and analytics for loaded APs (with large numbers of active clients) amongst a set of unloaded APs (without many/any active clients), calculations being done in parallel at different idle APs and the results aggregated at the controller AP.

[1] https://www.google.com/intl/en/ipv6/statistics.html