Department of Engineering Science ES465/CES 440, Intro. to Networking & Network Management Internet Trends http://www.sonoma.edu/users/k/kujoory References • “Computer Networks & Internet,” Douglas Comer, 6th ed, Pearson, 2014, Ch 2, Textbook, 5th ed, slides by Lami Kaya (LKaya@ieee.org) with some changes. • “Computer Networks,” A. Tanenbaum, 5th ed., Prentice Hall, 2011, ISBN: 13:978013212695-3. • “Computer & Communication Networks,” Nader F. Mir, 2nd ed, Prentice Hall, 2015, ISBN: 13: 9780133814743. • “Data Communications Networking,” Behrouz A. Forouzan, 4th ed, Mc-Graw Hill, 2007 • “Data & Computer Communications,” W. Stallings, 7th ed., Prentice Hall, 2004. • “Computer Networks: A Systems Approach," L. Peterson, B. Davie, 4th Ed., Morgan Kaufmann 2007. Ali Kujoory 6/30/2016 Not to be reproduced without permission 1 Topics Covered • 2.1 Introduction • 2.2 Resource Sharing • 2.3 Growth of the Internet • 2.4 From Resource Sharing to Communication • 2.5 From Text to Multimedia • 2.6 Recent Trends • 2.7 From Individual Computers to Cloud Computing Ali Kujoory 6/30/2016 Not to be reproduced without permission 2 2.1 Introduction • This chapter describes: – How data networking & the Internet have changed since their inception – A brief history of the Internet, highlighting the early motivations – A shift in emphasis from sharing centralized facilities to fully distributed information systems • Later chapters in this part of the text describes: – Specific Internet applications – Communication paradigms available on the Internet – The programming interface that Internet applications use to communicate Ali Kujoory 6/30/2016 Not to be reproduced without permission 3 2.2 Resource Sharing • Early computer networks were designed when computers were large & expensive & the main motivation was resource sharing – Networks were devised to connect multiple users • each with a screen & keyboard, to a large centralized computer – Later networks allowed multiple users to share peripheral devices • early networks were designed to permit sharing of expensive, centralized resources Ali Kujoory 6/30/2016 Not to be reproduced without permission 4 2.2 Resource Sharing • 1960s - Dept of Defense for Advanced Research Projects Agency (DARPA or ARPA) was interested in finding ways to share resources – Researchers needed powerful computers • ARPA did the following to achieve the visionary work: – gathered some of the best minds available – focused them on computer network research – hired contractors to turn the designs into a working system: ARPANET • but these computers were very expensive, & • ARPA budget was insufficient to fund many computers • The research turned out to be revolutionary – ARPA planned to interconnect all computers with a network & • devised software that would allow a researcher to use whichever computer was best suited to perform a given task Ali Kujoory 6/30/2016 Not to be reproduced without permission 5 2.3 Growth of the Internet • In less than 30 years – the Internet has grown from an early research prototype connecting a handful of sites to a global communication system – the rate of growth has been phenomenal • Fig 2.1 illustrates the growth with a graph – That uses a linear scale in which the y-axis represents values from zero through 550 million – Linear plots can be deceptive because they hide small details • To understand the early growth rate – Fig 2.2 shows the plot in log scale for the y-axis – That Internet has had exponential growth for over 25 years – Internet has been doubling in size every nine to fourteen months Ali Kujoory 6/30/2016 Not to be reproduced without permission 6 Ali Kujoory 6/30/2016 Not to be reproduced without permission 7 2.4 From Resource Sharing to Communication • As it grew, the Internet changed in two significant ways: – 1st, communication speeds increased dramatically – 2nd, new applications arose that appealed to a broad cross-section of society – Internet is no longer dominated by scientists & engineers, scientific applications, or access to computational resources Ali Kujoory 6/30/2016 • Two technological changes fueled a shift away from resource sharing to new applications: – Higher communication speeds enabled • applications to transfer large volumes of data quickly – The advent of powerful, affordable, personal computers provided • the computational power needed for complex computation & graphical displays, eliminating most of the demand for shared resources Not to be reproduced without permission 8 2.5 From Text to Multimedia • One of the most obvious shifts has occurred in the data being sent across the Internet • Fig 2.3 illustrates one aspect of the shift – That Internet communication initially involved textual data – By 1990s, applications arose that allowed users to transfer images easily – By late 1990s, users began sending video clips & full-motion videos Ali Kujoory 6/30/2016 Not to be reproduced without permission 9 2.5 From Text to Multimedia • Fig 2.4 illustrates that a similar transition has occurred in audio • Multimedia characterizes data that contains a combination of text, graphics, audio, & video • Much of the content on the Internet now consists of multimedia now • Also, quality has improved as higher bandwidths have made it possible to communicate high-resolution video & high-fidelity audio Ali Kujoory 6/30/2016 Not to be reproduced without permission 10 2.6 Recent Trends • New technologies & new applications continue to emerge • Some of the most significant transitions have occurred as traditional communication systems moved from analog to digital, e.g., – Voice telephone network & cable television adopted Internet technology – Also, support for mobile users is accelerating • Fig 2.5 lists some of the changes • One of the most interesting aspects of the Internet arises – from the way that Internet applications change even though the underlying technology essentially remains the same • Fig 2.6 lists types of applications that have emerged Ali Kujoory 6/30/2016 Not to be reproduced without permission 11 2.6 Recent Trends Fig 2.5 Example of transitions in networking & the Internet Fig 2.6 Examples of popular applications Ali Kujoory 6/30/2016 Not to be reproduced without permission 12 2.6 Recent Trends • The availability of highquality teleconferencing systems such as Cisco's TelePresence, is significant for businesses – because such systems permit meetings to occur with out travel expense • in many businesses travel expenses have reduced significantly Ali Kujoory 6/30/2016 • Some social networking applications such as – Facebook, 2nd, Life, YouTube • Social network apps are fascinating – they have created new social connections - sets of people know each other only through the Internet – sociologists suggest that such applications will enable more people to find others with shared interests & will foster small social groups Not to be reproduced without permission 13 2.7 From Individual Computers to Cloud Computing • Internet has brought in another big change in digital world by Cloud computing • In early 2000, companies realized that high-speed Internet connections would allow them to offer – computing & data storage services that can be much cheaper for the user than if the user implements on their own • Companies started to become cloud provider in their large cloud data centers that – contains many servers (computers) & disks connected to the Internet Ali Kujoory 6/30/2016 • So users including small companies contracted cloud services • An individual with a smart phone or a tablet can rent storage in the cloud to keep – music, pictures, videos & other files to access from anywhere & for back up & – would not need to worry about software, hardware, or maintenance • Cloud services are elastic – a customer only pays for resources actually used Not to be reproduced without permission 14