Elementary Information Security, 3rd Edition

▶ 11.2 Combining Computer Networks

The telephone system evolved over many decades. It could take years of planning and coordination each time they attempted to interconnect two or more existing networks. Matters could be even worse when connecting networks that developed in different countries or on different continents. The separate networks often used different wiring techniques or voltages or signals to make and route calls. They had to develop a coordinated way to handle the differences before a call from one system could be completed in another. The earliest techniques involved switchboards handled manually by human operators. As automatic call routing evolved, switchboards and operators were replaced with automatic routing equipment. ...