Introduction to Networking
Brief History and Evolution of Networks Who's Who Data Communication
Brief History and Evolution of Networks
The 18th century - era of the great mechanical systems, Industrial Revolution The 19th century - age of the steam engine The 20th century - key technology was information gathering, processing, and distribution • Worldwide telephone networks • Invention of radio and television • Birth and growth of the computer industry • Launching of communication satellites The old model of a single computer serving all of the organization's computational needs has been replaced by one in which a large number of separate but interconnected computers do the job These systems are called computer networks. The ARPANET (Advanced Research Projects Agency Network) developed by ARPA of the United States Department of Defense, was the world's first computer network. (1960s)
Introduction Throughout we will use the term ''computer network'' to mean a collection of autonomous computers interconnected by a single technology, two computers are said to be interconnected if they are able to exchange information The connection need not be via a copper wire; fiber optics, microwaves, infrared, and communication satellites can also be used
Who's Who ?
PTT – Post Telephone and Telegraph administration. One of the many national bodies responsible for providing communications services in a particular country. In Sri Lanka the SLT
ITU - International Telecommunication Union
Tasks • Standardization • Allocation of the radio spectrum • Organizing interconnection arrangements between different countries
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ITU Telecommunication Standardization Sector (ITU-T) ITU Radio communication Sector (ITU-R) ITU Telecommunication Development Sector (ITU-D)
The standards are called "Recommendations" ANSI - American National Standards Institute ISO - International Organization for Standardization (International Standards Organization)...