[e2e] Data flow models for real-time applications

[Christian Huitema]

> But there are a number of other applications that have real-time
> characteristics that are not play-back applications. Sensor traffic
> comes to mind; certain classes of sensors generate traffic at a
> certain rate, either regardless of circumstances or under certain
> circumstances, and if it doesn't get through there is no
> retransmission on the theory that it wasn't all that important. An
> example that has been proposed is with the CalTech Earthquake lab; if
> they had cheap seismometers built into set-top boxes in people's homes
> (say), whenever there is a jiggle above some threshold they could get
> an arbitrary number of UDP reports with a GPS location and a seismic
> reading. Now, that would have the characteristics of a DDOS attack
> (when there is a jiggle near CalTech, a *lot* of homes might be
> affected), so they had jolly well better have enough bandwidth in
> place.

Either that, or make the sensors a tiny bit smarter. I am sure there are lots of publish papers on how to make distributed systems like these more efficient, e.g. have a varying fraction of the sensors activated at some time, with the fraction varying based on activity level...

-- Christian Huitema