rol from the battle field. The desired system was to have a large degree of redundancy, and be capable of working in networks with different bandwidths. The project was initiated and funded through the Advanced Research Projects Agency (ARPA) of the United States. The merging of the two streams, research into packet-switched communications and funding for building such an experimental network gave birth to the Arpanet, a data commu- nications network connecting several universities and research institutions in the late 1960s. Kleinrock who was by then a professor at UCLA was one of the architects of the Arpanet and helped build the first equipment realising packet-switched communications. As minicomputers entered the workplace in the 1980s and intra-office and inter-office data communications became widespread, internetworking grew - and the entire interconnected data communications network came to be known as the Internet. Services such as email, World Wide Web, automated supply chain, social networks and SO on are built over this platform [3, 4]. Data Communications Electrical telegraphy and electrical telephony can be considered major technological break- throughs. While they were based on prior discoveries and inventions and the inventors stood on the 'shoulders of giants', they still represented major milestones and advances in the history of telecommunications. Packet-switched mode of telecommunications can be considered alongside these advances as a major milestone. Traditional telegraphy and telephony use the 'circuit-switched' modes of telecommunica- tions. This means that an end-to-end circuit is first established between two parties over which a call is made. When the call ends the circuit is disconnected (switched off) SO it can be used to carry another call between two different parties. The circuit may physically be a channel in a specific frequency band of media such as wire or air. Telecommunications between computers or other machines on what has come to be known especially as the internet uses a