Baran envisioned a network of unmanned nodes that would act as switches, routing information from one node to another to their final destinations. The nodes would use a scheme Baran called "hot-potato routing" or ."

These ideas were so cutting edge at the time that AT&T rejected them, saying they wouldn't work, according to longtime friend and fellow network pioneer Vinton Cerf, quoted in a . 

Baran is typically considered one of three people whose contributions led to the development of packet switching, along with Donald Davies and Leonard Kleinrock.

Following his years at RAND, Baran became something of a serial entrepreneur. He founded a long-range forecasting outfit called Institute for the Future in 1968, and in the mid-1980s co-founded wireless Internet access pioneer Metricom (known for its Ricochet service) and later InterFax, Com21 and GoBackTV. 

Early in his career he worked as a technician on the historic Univac 1 computer after graduating from Drexel University.