APPENDIX A Network Technology

NETWORK BUILDING BLOCKS

The essence of an electronic network is connectivity between computers. The first computers ran as stand-alone machines that could be accessed only from their immediate physical location.1 Later, they became reachable through "dumb" terminals connected to hard-wired lines and dial-in ports. More recently, computer-to-computer connections were implemented through hard-wired and dial-in ports and through local area and wide area networks. Today, many computers participate in the growing global network, sometimes referred to as "the net." One of the main components of this network is the Internet, which itself is a network of networks with international reach. Transmissions over the global network may pass through several computers and network gateways before reaching their final destinations.

When computers are networked, the network must support a method of uniquely addressing the various computers connected to it. Any user regardless of location (but connected to the network) who wishes

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Even today, there are valid reasons to establish "islands" of computing capability that do not interact with other systems. For example, a corporation may choose not to connect its network or its individual computers to the external world because of security concerns. Still, recent experience demonstrates that important and powerful synergistic effects are possible when many individual computing elements are connected to each other.



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