CS 4700 / CS 5700 Network Fundamentals Lecture 2: History (Hint: Al Gore *did* have a small role) Revised 1/11/16 What is a Communication Network? 2 A communications network is a network of links and nodes arranged so that messages may be passed from one part of the network to another
Networks are key for: What are Speed nodes and links? People and roads Distance Telephones and switches Computers and routers What is a message? Information
Networks are Fundamental 3 Smoke Signals! Networks are Old 4 2400 BC: courier networks in Egypt 550 BC: postal service invented in Persia Problems: Speed Reliability
Security Towards Electric Communication 5 1837: Telegraph invented by Samuel Morse Distance: 10 miles Higher compression
Speed: 10 words per minute = faster speeds In use until 1985! Key challenge: how to encode information? Originally used unary encoding A B C D
E Next generation: binary encoding A B C D E Telephony 6 1876 Alexander Graham Bell invents the telephone
Advantages Key challenge: how to scale the network? Originally, phones were directly connected Easy to all use O(n ) complexity; n*(n1)/2 Switching mitigates complexity 1878: Switching 1937: Trunk lines + multiplexing Makes cable
management tractable Problems Manual switching 1918: cross country call took 15 minutes to set up 2 Growth of the Telephone Network 7
1881: 1885: 1892: 1903: 1915: 1927: 1937: 1946: Twisted pair for local loops AT&T formed Automatic telephone switches 3 million telephones in the US First transcontinental cable
First transatlantic cable first round-the-world call National numbering plan Evolution of switching 8 Telephone networks are circuit switched Problems
Each call reserves resources end-to-end Provides excellent quality of service Resource intense (what if the circuit is idle?) Complex network components (per circuit state, security) Packet switching No connection state, network is store-and-forward Minimal network assumptions Statistical multiplexing gives high overall utilization
The Worlds Most Successful Computer Science Research Project 9 History of the Internet 10
1961: 1962: 1965: 1967: 1969: UCLA 1970: 1972: 1972: 1972: Kleinrock @ MIT: packet-switched network Lickliders vision of Galactic Network Roberts connects computers over phone line Roberts publishes vision of ARPANET BBN installs first InterfaceMsgProcessor at Network Control Protocol (NCP) Public demonstration of ARPANET
Kahn @ DARPA advocates Open Architecture Vint Cerf @ Stanford writes TCP The Internet, Explained by Vint Cerf 11 Vint Cerf on Colbert Report (Part 1) The 1960s 13 1971 14
1973 15 More from Vint 16 Vint Cerf on Colbert Report (Part 2) Growing Pains 17 Problem: early networks used incompatible protocols
Kahns Ground Rules 18 Each network is independent, cannot be forced to change 2. Best-effort communication (i.e. no guarantees) 3. Routers connect networks 4. No global control 1. Principles behind the development of IP Led to the Internet as we know it Internet is still structured as independent
The Birth of Routing 19 Trivia Kahn believed that there would only be ~20 networks. He was way off. Why? Internet Applications Over Time 20
1972: Email 1973: Telnet remote access to computing 1982: DNS phonebook of the Internet 1985: FTP remote file access
1989: NFS remote file systems 1991: The World Wide Web (WWW) goes public 1995: SSH secure remote shell access 1995-1997: Instant messaging (ICQ, AIM) 1998: Google 1999: Napster, birth of P2P 2001: Bittorrent Invented by 2004: Facebook 2005: YouTube Shawn Fanning 2006: Twitter at NEU 2007: The iPhone 2016: IoT, Oculus Rift, ? What is next?
2000 21 2006 22 2009 23 2010 24 More Internet History 25
1974: Cerf and Kahn paper on TCP (IP kept separate) 1980: TCP/IP adopted as defense standard 1983: ARPANET and MILNET split 1983: Global NCP to TCP/IP flag day 198x: Internet melts down due to congestion 1986: Van Jacobson saves the Internet (BSD TCP) 1987: NSFNET merges with other networks 1988: Deering and Cheriton propose multicast
199x: QoS rises and falls, ATM rises and falls 1994: NSF backbone dismantled, private backbone 1999-present: The Internet boom and bust and boom 2007: Release of iPhone, rise of Mobile Internet 201x-present: Rise of software-defined networks, smart homes Enough about history 26 This is not a history course The Internet is constantly evolving I will teach you about
The principles on which it was founded The fundamental protocols that drive it The various applications built atop it How these networks are deployed today Future directions it might go Takeaways 27
Communication is fundamental to human nature Encoding Key concepts have existed for a long time Speed/bandwidth Latency Switching Packets vs. circuits
Cable management Multiplexing Routing The Internet has changed the world Promise of free ($) and free (freedom) communication Shrunk the world
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