Paul Baran was a visionary, but it is worth noting that there are multiple versions of the early history.
First read http://www.livinginternet.com/i/iw_packet_inv.htm for the basic, non-controversial background. You'll find out that packet switching was invented first by Paul Baran. Then independently by Donald Davies. And then Arpanet was created by Leonard Kleinrock.
The controversy is over whose work Leonard Kleinrock was aware of and used. The version that I've heard is that he was more aware of Donald Davies work than Paul Baran's. Which is why we call the technology packet switching as Davies did today rather than block switching as Baran did. According to this version, Paul Baran did his work first, but was not in the direct path to the actual ARPANET.
The other version, of course, is that Paul Baran's work was the basis of Leonard Kleinrock's work. Which would make ARPANET an entirely American invention, and would make Donald Davies an interesting side note.
First read http://www.livinginternet.com/i/iw_packet_inv.htm for the basic, non-controversial background. You'll find out that packet switching was invented first by Paul Baran. Then independently by Donald Davies. And then Arpanet was created by Leonard Kleinrock.
The controversy is over whose work Leonard Kleinrock was aware of and used. The version that I've heard is that he was more aware of Donald Davies work than Paul Baran's. Which is why we call the technology packet switching as Davies did today rather than block switching as Baran did. According to this version, Paul Baran did his work first, but was not in the direct path to the actual ARPANET.
The other version, of course, is that Paul Baran's work was the basis of Leonard Kleinrock's work. Which would make ARPANET an entirely American invention, and would make Donald Davies an interesting side note.