Our modern business world depends on the use of digital communication techniques. Analogue transmission systems relied on end to end connection, and hence contributed greatly to the cost of business data transmission. The advent of packet switching and pulse code modulation produced low-cost flexible transmission of both voice and data. The ancestor of modern systems was probably the telex system which sent packets of information around a worldwide and (generally unsung) network
The development of the Internet meant that the whole world is now virtual bus system with users having the ability to access a wide variety of services. It is difficult to divorce the development of networking from the development software. I once set up a Linux Web server for use in the University where I taught. The support community for users and developers was absolutely amazing.
For many years the electromechanical telephone exchanges were the only option as the electronics was not yet reliable enough to be used on public systems. For example, every telephone exchange had to have a backup battery system to enable the exchange to operate for at least 48 hours in case of power failure. It is interesting to notice how many telephone exchange buildings have been sold off, and existing ones have a lot of spare space due to the compact electronic digital systems
When I started work there were no public semiconductor electronic telephone exchanges, they were all electromechanical. Electromechanical switching systems such as the Strowger system were marvels of technical development. I always found it fascinating to watch a branch or main telephone exchange in full operation. Sparks flew but it worked very efficiently.
At the time I started in 1960 some telephone exchanges still using paper covered wire. This created problems as a mouse infestation could cause chaos as the mice stripped the paper off to make their nests
We were told that automatic exchanges exported particularly to South American countries suffered nervous breakdowns due to overuse as everybody wanted to try it. There was no mechanical reason for this breakdown but one can only assume that the complicated nature of the switches exhibited some form of animal behaviour