An Introduction to Computer Networks Lecture 1: Introduction University of Tehran Dept. of EE and Computer Engineering By: Dr. Nasser Yazdani Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Outline Agenda Policy, Grading, reading materials, etc. Communication. Overview and history of the Internet Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Agenda To establish a base for future computer network work and study. Review networking technologies, protocols. Finally, prepare to perform some projects in computer networks which are essential in national development, designing and building switches, routers, etc. Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Course Materials Course Web page http://ece.ut.ac.ir/classpages/Networks/ visit regularly Textbook “Computer Networks, A system approach”. Peterson & Davie 3rd edition Other useful books A. Tanenbaum, Computer Networks R. Stevens, TCP/IP Illustrated (vol 1) S. Keshav, An Engineering Approach to Computer Networking Kurose and Ross, Computer Networking Walrand, Communication Networks, 2nd Ed Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Grading Homework assignments, around %30 4-5 five homework Late penalties! Course involve programming on C/C++ in Unix environment. Few small quizs around %10 Midterm exam around %30. Final exam around %30. Note: There is a %40 cut off on total exam points. Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Prerequisition General knowledge in Computer engineering. C/C++ programming. Knowledge of UNIX (LINUX) system and programming. Fluency in English, specially reading. Univ. ov Tehran Introduction to Computer Network

How to survive this course Materials sound simple and easy, but they are not. Do not leave everything to the exam night!. Not copy the homework!, try them by yourself. You can read the course by yourself, but the class makes the life for you easier. Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Some Ground Rules Let’s make this educational and enjoyable. It’s a big class, I enjoy questions and ideas from the class. Ask questions and raise points. Identify yourself when you ask questions. Listen to other people’s questions. Be here. Be here on time. Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Special Warning This is computer network course not queue theory! There are not much Mathematics (Attention for EE students!) There are programming in the course Still we think the course is not easy. Needs a lot of work. Indeed, It is in a higher level than just sending signals. Univ. ov Tehran Introduction to Computer Network

Why Study Computer Network? To graduate! To get a degree To be engineer. It is good in the society, for prestige, marriage, etc. Networking is everything! It does not matter what you know. It is matter who you know. Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network What you Learn? Insight: key concepts in networking Protocols Layering Resource allocation Performance evaluation Knowledge: how the Internet works Internet architecture IP protocol suite Applications (Web, e-mail, P2P, …) Skill: network programming Socket programming Designing and implementing protocols Univ. ov Tehran Introduction to Computer Network

Communication as a human being need. Base of community Collection of trees is not a community. Transferring data, knowledge, experience among people Base of civilization. Psycological need. Love, affection. Just talking. Releasing someone. Base of Culture. Univ. ov Tehran Introduction to Computer Network

Primary Communication means Language Conventions Body Language, Meta language. Universal. Problems: Limited in Time (delay) and space (domain). We are struggling all the history to overcome these limitation. Univ. ov Tehran Introduction to Computer Network

Communication elements Producer, Sender Speaker (in conversation) Consumer, Receiver Listener They both do have processing-limitation Message- Talk Transfer media, like air Substance Capacity (very limited) Delay (considerable) Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Type of communication One to one Direct talk. One to many Talks, conferencing Many to Many Like mass media, new paper. Domain of communication Small, primary society Medium, more developed society. Large, more advance society. Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network First Step- Writing One of the most important human being invention. (Why?) Overcome the primary limitations. Time: By writing it down. Space: Distributing more copies, library, post, etc. Problems: Indirect Communication, Through paper. Slow in producing and consuming Need proficiency Encoding message Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Next Step- Mailing Distribute messages as fast as and as far as possible. Overcome mostly space limitation, while widen the domain of communication. Media- human being network system. Indirect communication. Encoded message Slow. Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network New wave- Telegraph In 1837, Samuel B. Morse invented it. Text message is encoded by dot and dashed (binary, digital system). Message switching, human coding for efficiency, and hop by hop routing. Fast transmission, (Time limitation) Slow production (25-30 word/min) The daily Telegraph. Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Telephone In 1876, While working on multiplexing telegraph, invented By A. Graham Bell. One to one, completely real time communication. No need to proficiency. Fast, (time limitation) Easy to use or produce data. Exponential growths, 1000 in 1877 to 50,000 in 1880 Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Broadcast media Printing, news papers, Easy to reproduce the same data. Easy to distribute message. Slow in producing and contribution. Radio Fast in producing and contribution of message. Limited of type of message, only voice. TV All like radio, but with reach data. Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Fast in producing, processing, distributing and consuming messages. No limitation in time and space. Support different type of communication. Mass media, news group. One to many, mailing list. One to one, mail, chat, talk. Support of different type of message, data Only problem, need proficiency. Univ. ov Tehran Introduction to Computer Network

History of the Internet 70’s: started as a research project, 56 kbps, < 100 computers 80-83: ARPANET and MILNET split, 85-86: NSF builds NSFNET as backbone, links 6 Supercomputer centers, 1.5 Mbps, 10,000 computers 87-90: link regional networks, NSI (NASA), ESNet(DOE), DARTnet, TWBNet (DARPA), 100,000 computers 90-92: NSFNET moves to 45 Mbps, 16 mid-level networks 94: NSF backbone dismantled, multiple private backbones Today: backbones run at 10 Gbps, around160 millions computers in 160 countries Univ. ov Tehran Introduction to Computer Network

Growth of the Internet Number of Hosts on the Internet: Aug. 1981 213 Oct. 1984 1,024 Dec. 1987 28,174 Oct. 1990 313,000 Oct. 1993 2,056,000 Apr. 1995 5,706,000 Jul. 1997 19,540,000 Jul. 1999 59,249,900 Jul. 2001 117,288,000 Data available at: http://www.netsizer.com/ Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Recent Growth (by 2004) Univ. ov Tehran Introduction to Computer Network

Services Provided by the Internet Shared access to computing resources telnet (1970’s) Shared access to data/files FTP, NFS, AFS (1980’s) Communication medium over which people interact email (1980’s), on-line chat rooms, instant messaging (1990’s) audio, video (1990’s) replacing telephone network? A medium for information dissemination USENET (1980’s) WWW (1990’s) replacing newspaper, magazine? replacing radio, CD, TV? Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Today’s Vision Everything is digital: voice, video, music, pictures, live events Everything is on-line: bank statement, medical record, books, airline schedule, weather, highway traffic, toaster, refrigerator … Everyone is connected: doctor, teacher, broker, mother, son, friends, enemies Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network What is Next? Electronic commerce virtual enterprise Internet entertainment interactive sitcom World as a small village community organized according to interests enhanced understanding among diverse groups Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network What is Next? Electronic democracy little people can voice their opinions to the whole world little people can coordinate their actions bridge the gap between information haves and have-not’s Electronic terrorism hacker can bring the whole world to its knee Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Industrial Players Telephone companies own long-haul and access communication links, customers Cable companies own access links Wireless/Satellite companies alternative communication links Utility companies: power, water, railway own right of way to lay down more wires Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Industrial Players Medium companies own content Internet Service Providers Equipment companies switches/routers, chips, optics, computers Software companies Univ. ov Tehran Introduction to Computer Network

Commercial Internet after 1994 Joe's Company Stanford Berkeley Campus Network Regional ISP Bartnet Xerox Parc SprintNet America On Line UUnet NSF Network IBM NSF Network Modem Internet MCI IBM Univ. ov Tehran Introduction to Computer Network

Internet Physical Infrastructure Backbone ISP ISP Residential Access Modem DSL Cable modem Satellite Enterprise/ISP access, Backbone transmission T1/T3, DS-1 DS-3 OC-3, OC-12 ATM vs. SONET, vs. WDM Campus network Ethernet, ATM Internet Service Providers access, regional, backbone Point of Presence (POP) Network Access Point (NAP) Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Homework 0 Install Linux on your computer Try to be professional on Unix if you are not so. For Communication Engineer: Learn C/C++ programming well on Unix environment. Your first assignment will come soon!. Univ. ov Tehran Introduction to Computer Network

Introduction to Computer Network Next Lecture Computer network foundation. Read Chapter 1 Univ. ov Tehran Introduction to Computer Network