1960s
- modem communications
- computer/terminal to computer
- telephone based
1969
- experimental ARPANET begun
1970s
- emergence of LANs
- circuit board to circuit board
- bus and ring architectures
- ARPA funded communications research
- emergence of WANs
- site to site communication
- telephone based
- dedicated computers
- pass through routing
- proliferation of incompatible LANs & WANs