Computer Networks (EENG 4810)

  • View
    29

  • Download
    0

Embed Size (px)

DESCRIPTION

Computer Networks (EENG 4810). Course Objectives & Scope. In this class, you are expected to learn -. A brief History of Computer Networks Categorization of Computer Networks Network Services and Internet Perspective Network Components- Nuts and Bolts View - PowerPoint PPT Presentation

Text of Computer Networks (EENG 4810)

  • Computer Networks- Course Objectives & Scope - 1*Computer Networks (EENG 4810)

    Computer Networks- Course Objectives & Scope - 1

  • Computer Networks- Course Objectives & Scope - 2*Course Objectives & Scope

    Computer Networks- Course Objectives & Scope - 2

  • Computer Networks- Course Objectives & Scope - 3*In this class, you are expected to learn -

    A brief History of Computer Networks

    Categorization of Computer Networks

    Network Services and Internet Perspective

    Network Components- Nuts and Bolts View

    General Concepts of Network Design

    Protocols and Layered Communication Architecture

    Network Programming

    Computer Networks- Course Objectives & Scope - 3

  • Computer Networks- Course Objectives & Scope - 4*This class, however, does not deal with -

    Network Hardware Design

    Comparative analyses of different protocol standards

    Special purpose networks such as ad hoc sensor nets

    Applications of Queuing Theory to Network traffic control

    Computer Networks- Course Objectives & Scope - 4

  • *Lesson 1:History of Computer Networks

  • History of Computer Networks - 1*Preview of the Lesson 1In this lesson, we cover History of Computer Networks organized into approximately 5 decades.

    In passing, we get a hang of what all a computer network can do

    History of Computer Networks - 1

  • History of Computer Networks- 2*History of Computer NetworksDevelopment of Packet Switching: 1961-72

    Proprietary Networks and Internetworking: 1972-80

    Proliferation of Networks: 1980-90

    Internet Explosion: 1990-2000

    Recent Developments: Bubble burst?

    History of Computer Networks- 2

  • Lesson 1: History of Computer Networks - 3*Development of Packet Switching: 1961-72Telephone network - Worlds dominant communication network , uses circuit switching. (Early 1960s)Three research groups around the world independently invented packet switching (1964 1967)Leonard Kleinrock at MIT used queuing theory to demonstrate effectiveness of packet switching for bursty trafficPaul Baran of Rand Institute investigated packet switching for secure voice communication over military networksDonald Davies and Roger Scantlebury were developing ideas on packet switching at the National Physical Lab, England.

    Lesson 1: History of Computer Networks - 3

  • Lesson 1: History of Computer Networks - 4*Development of Packet Switching: 1961-72(continued)J.C.R. Licklider and Laurence Roberts led the CS program at ARPA (Advanced Projects Research Agency) and published a plan for ARPAnet in 1967.Arpanet was the ancestor of todays Internet.Early Packet switches were known as Interface Message Processors (IMPs). BBN got the contract.First IMP was installed at UCLA on Labor Day 1969 under Kleinrocks supervision. Later 3 more at SRI, UCSB and University of Utah.

    Lesson 1: History of Computer Networks - 4

  • Lesson 1: History of Computer Networks - 5*Leonard Kleinrock with IMP

    Lesson 1: History of Computer Networks - 5

  • Lesson 1: History of Computer Networks - 6*Development of Packet Switching: 1961-72(continued)First use of the net of 4 nodes was remote login from UCLA to SRI; it resulted in system crash.Robert Kahn demonstrated 15-node ARPAnet in 1972 ICCN. First host to host protocol was Network Control Protocol (NCP). Ray Tomlinson at BBN wrote the first e-mail program in 1972.

    Lesson 1: History of Computer Networks - 6

  • History of Computer Networks - 7*Proprietary Networks and Internet 1972-80ALOHAnet- microwave satellite net linking universities on Hawaii islands (Norman Abramson 1970).

    Telenet- a BBN commercial packet network and Cyclades- a French Packet Net by Louis Pouzin.

    Time-sharing networks such as Tymnet and GE Information Services Net (late 60s and early 70s).

    Metcalfes PhD thesis proposing Ethernet.

    History of Computer Networks - 7

  • History of Computer Networks - 8*Proprietary Networks and Internet 1972-80(Continued)Proprietary Networks such asIBMs (1969-74) System Network Architecture (SNA) paralleling the ARPAnet (Schwartz 1977).DECs DECnet and Xerox corporations XNA.Vincent Cerf and Robert Kahn (Cerf 1974)- Architecture for interconnecting Networks (They coined the word Internet for network of networks).DARPAs packet satellite and packet-radio networks (Kahn 1978).

    History of Computer Networks - 8

  • History of Computer Networks - 9*Proprietary Networks and Internet 1972-80(Early Internet Features)Cerf and Kahns TCP (quite different from now)It combined reliable in-sequence delivery of data by end-system retransmission (as now) with forwarding (as IP now)Realization of usefulness of separation of unreliable, non-flow controlled end-to end transport service for applications such as packetized voice led to separation of IP.Three internet protocols TCP, IP and UDP - conceptually in place by the end of 1970s.Main features of their InterNet- Minimalism, autonomy (no internal changes required for interconnection), Best effort delivery, stateless routers and decentalized control.

    History of Computer Networks - 9

  • Lesson 1: History of Computer Networks - 10*Proprietary Networks and Internet 1972-80(Early Ethernet Features)Abramsons ALOHA protocol- a multiple-access protocol for communication among geographically distributed users by a single shared broadcast medium.Metcalfe and Boggs EtherNet protocol for wire-based shared networks was originally motivated by the need to connect multiple PCprinters

    Lesson 1: History of Computer Networks - 10

  • History of Computer Networks - 11*Proliferation of Networks 1980-90100 nodes by late 70s New national networks (100,000 by the end of 80s)BITNET for email and FTP services among many North East UniversitiesCSNET (computer Science Network) for researchers with no access to APRPAnet.NSF-net for access to NSF-sponsored super-computing centersStarting with a backbone of 56 kbps, NSF net was running at 1.5 Mbps by the end of the decade.

    History of Computer Networks - 11

  • Lesson 1: History of Computer Networks - 12*Proliferation of Networks 1980-90 (Continued)

    Simple Message Transfer Protocol (SMTP): E-Mail 1982Deployment of TCP /IP replacing NCP (Jan. 1, 1983)FTP- The File Transfer Protocol defined (1983).Host-based TCP Congestion Control (Jacobson 1988).Domain Name System (DNS)- mapping between human readable Internet computer name and 32-bit IP address.

    Lesson 1: History of Computer Networks - 12

  • Lesson 1: History of Computer Networks - 14*Proliferation of Networks 1980-90(The Minitel Project)French Minitel project paralleling ARPAnetAmbitious projest sponsored by the French GovernmentX.25 protocol suite using virtual circuitsBy mid-90s, it offered more than 20, 000 services- from home banking to research databaseUsed by more than 20% of the populationGenerated over $1 billion in revenueWas in most French homes 10 years before Americans had ever heard of the Internet.

    Lesson 1: History of Computer Networks - 14

  • History of Computer Networks -15*Internet Explosion: The1990sEarly 90s Arpanet decommissioned as Milnet and Defense Data Net grew enough to carry all defense-related traffic.NSF lifted restrictions on commercial use of NSFnet (1991). NSFnet began to serve as a backbone and was later decommissioned it in 1995.Web invented at CERN by Tim Berners-Lee (89-91) Developed intial versions of HTML, HTTP, a web server and a web browser - Based on the original work on Hypertext in 1940s by Bush (1945) and in 1960s by Ted NelsonMarc Andreesen developed Mosaic- Popular GUI browser.

    History of Computer Networks -15

  • History of Computer Networks -16*Internet Explosion: First half of1990sMarc Andreesen and Jim Clark formed Mosaic Communications in 1994(it later became Netscape).

    By 1995, University students were able surf web.

    Big and small companies started transacting on the web and transact commerce over the web.

    History of Computer Networks -16

  • History of Computer Networks -17*Internet Explosion: Second half of1990sMicrosoft (MS) started making browsers (1996) and this started the war with NetScape which MS won later.E-mail evolved with address books, attachments, hot links, multimedia support. 4 Killer applicationsWeb accessible emailWeb browsing & internet commerceinstant messaging with contact lists pioneered by ICQpeer-to-peer file sharing of MP3s , pioneered by Napster .By late 90s, 50 million computers with 100+ million users on the web. 1 GBs Back bone link speeds achieved.

    History of Computer Networks -17

  • History of Computer Networks -18*Recent DevelopmentsFinancial turmoil, many start-ups collapsed. Still many companies like eBay, Yahoo, Amazon and Cisco emerged as winners despite setbacks in their stock prices.Advances in content distribution, internet telephony, high speed LANs and fast routers3 Important developmentsHigh Speed Access Internet Access (Cable/DSL/Wireless LANs)Secure applicationsP2P (Point-to-point Networking)

    History of Computer Networks -18

  • History of Computer Networks -19*Three Important Recent Developments I- High Speed Internet Access

    Increased penetration of broadband residential Internet via Cable and DSL with applications such as high-quality Video on Demand and high quality Video ConferencingIncreased ubiquity of public Wi-Fi nets (with 11 Mbps and higher speeds)Internet access via mobile phones of 3rd Generation & Beyond.

    History of Computer Networks -19

  • History of Computer Networks -20*Three Important Recent DevelopmentsII- SecurityIntrusion detection methods for early warnin