To the point of ‘how the Internet blacked out’ - a lot of what you think of as ‘phone’ today actually goes via IP over data, not analog voice. It would mean we all have to turn back on our land lines, which would take ages and a lot of business and logistics would be pretty rough for a while. Those few places with working phones would have lines of people waiting to use them until it was restored more widely.
To the point of ‘how the Internet blacked out’ - a lot of what you think of as ‘phone’ today actually goes via IP over data, not analog voice. It would mean we all have to turn back on our land lines, which would take ages and a lot of business and logistics would be pretty rough for a while. Those few places with working phones would have lines of people waiting to use them until it was restored more widely.