1 The Global Communications Infrastructure

We are in a period of rapid advance in the collaboration of computer systems to perform a wider range of activity than ever before. Traditional computer communications to support human-driven remote logon, e-mail, file-transfer, and latterly the World Wide Web (WWW) are being supplemented by new applications requiring increasingly complex exchanges of information both between computer systems and between appliances with embedded computer chips.

Some of these exchanges of information continue to be human-initiated, such as bidding at auctions, money wallet transfers, electronic transactions, voting support, or interactive video. Others are designed for automatic and autonomous computer-to-computer communication in support of such diverse activities as cellular telephones (and other telephony applications), meter reading, pollution recording, air traffic control, control of power distribution, and applications in the home for control of appliances.

In all cases there is a requirement for the detailed specification of the exchanges the computers are to perform, and for the implementation of software to support those exchanges.

The most basic support for many of these exchanges today is provided by the use of TCP/IP and the Internet, but other carrier protocols are still in use, particularly in the telecommunications area. However, the specification of the data formats for messages that are to be passed using TCP (or other carriers) requires the design and clear specification of application protocols, followed by (or in parallel with) implementation of those protocols.

For communication to be possible between applications and devices produced by different vendors,...