A Comparison of PSTN and IP Traffic From 1997 to 2015

A Comparison of PSTN and IP Traffic From 1997 to 2015.  Slides start on page #4.

[slideshare id=8515037&doc=acomparisonofpstnandiptrafficfrom1997to2015-110705135902-phpapp02&type=d]

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A couple of days ago the Wall Street Journal reported

There is a misconception that engineering wins in the end.