Hello Jonathan,
The overlap or common area between the VNI Forecast and the GCI Forecast is "Data Center to User Traffic". In the image you provided from the current GCI Forecast summary (Data Center Ip Traffic.PNG), you'll note that the Data Center to User (top/first row of the table) traffic projected for 2020 is 2,183 exabytes (which can be rounded to 2.2 zettabytes). That amount (2.2 zettabytes) is equivalent to what is shown in circle B ( Data Center to User) of the other image you provided (Consolidated Cisco GCI & VNI.PNG) -- which also shows 2.2 zettabytes.
The last image that you shared (IP Traffic VNI.PNG) is from our most recent Complete VNI Forecast. It was just released this month (June 2017) and it covers a different forecast period (2016 - 2021). The previous attachments/images cover the 2015 - 2020 forecast period. We are tentatively planning to develop an updated GCI report in the Fall of 2017 that will cover the 2016 - 2021 forecast period. The annual run rate of global IP traffic (or Data Center to User Traffic) per the recent 2017 VNI Complete Forecast is 3.3 zettabytes per year. You can expect the Data Center to User Traffic in the updated GCI report later this year to match that annual traffic volume (3.3 zettabytes). I hope this is helpful.
