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Source: Dr. Chus Lecture Notes, 2000 IST 220-002: Networking and TelecommunicationsChapter 1: Introduction to Computer Networks Data Communication Dr. Lee Giles 001 Thomas Building, School of IST Phone 865 7884 Email: giles@ Computer Systems Redefined Information Communication Generation and transfer of information is critical to today’s businesses Flow of information both mirror and shape organizational structures Networks are the enabling technology for this process The “Manager’s Dilemma” Technology is necessary for competitiveness Cost of technology has decreased Reliance on technology has increased Number of choices have increased Choices are both more difficult and more important What is Data Communication? Communication of data between sources Data formats – analog or digital or both Data travels by a medium Wires Space Essentials of Data Communication Message Sender Receiver Medium Understandability Error detection Security Types of Messages Protocols Enables communication – how we communicate (convention used for establishing transmission rules) When Where How What with How much Protocols Important Dates in the History of Data Communications (1) 1837 – Invention of the telegraph 1876 – Invention of the telephone 1947 – Invention of the transistor (replaced vacuum tubes) 1948 – First commercial computer installed, the UNIVAC I 1958 – First U.S. Communications satellite sent into orbit 1959 – FCC approves private microwave communications networks 1964 – Packet switching network concept proposed by the Rand Corporation 1966 – IBMs binary synchronous (BISYNC or BSC) protocol announced 1969 – ARPANET, first packet switching network (later to become the Internet), begins operation Important Dates in the History of Data Communications (2) 1972 – Ethernet local area network specifications formulated 1972 – IBMs Synchronous Data Link Control (SDLC) protocol announced 1974 – IBM announces its Systems Network Architecture (SNA) 1975 – Personal computers int