Van Jacobson, "A New Way to look at Networking" https://www.youtube.com/watch?v=8Z685OF-PS8
The resounding rejection of packet switching by period communications experts at https://youtu.be/8Z685OF-PS8?t=21m0s is awesome. Oh how the mighty have fallen!
This is a great talk from another networking legend: "Network Protocols: Myths, Missteps, and Mysteries" by Radia Perlman.
I love her personality and sense of humor, and it has tech content that is completely relevant today: https://www.youtube.com/watch?v=pfiMBegejQM