1. 1 CSE401N Computer Networking January 2006 S. M. Hasibul Haque Department of Computer Science BUET

2. 2 What is this course about? Introductory (first!) course in computer networking r learn principles of computer networking r learn practice of computer networking r Internet architecture/protocols as case study by the time you are finished …… Goals: r learn a lot (not just factoids, but principles and practice) r have fun (well, it should be interesting, at least)

3. 3 Course Information r Who is this course for? m Undergrads r Prerequisites: m Algorithms, Operating Systems, programming skills r Course materials: m text: Computer Networking: A Top Down Approach Featuring the Internet, J. Kurose & Keith Ross, Addison Wesley, 2000 m WWW readings m Class notes

4. 4 Administrative trivia’s r Textbook m Computer Networking: A Top- Down Approach Featuring the Internet, 2/e by Kurose and Ross r Reference books m Computer Networks, 4/e by Andrew S. Tanenbaum m Computer Networks, A system approach. 3/ed by Larry L. Paterson m Unix Network Programming by W. Richard Stevens

5. 5 Course Information (more) r Broadcast email: cse401n_jan06@yahoogroups.com m more later r Personnel m instructor S. M. Hasibul Haque hasibulhaque@cse.buet.ac.bd Hasibul_haque@yahoo.com office hours –Feel free to stop by if you see me. –e-mail is the best way to communicate with me

6. 6 What Are the Goals Of This Course? r Understand the Computer Network r Understand how Internet works m Its philosophy m Its protocols and mechanisms r Learn Network Programming r Have fun!

7. 7 What Will We Cover? r Internet architecture and design philosophy r applications m HTTP, Email, DNS,P2P, NP r transport services m reliability; congestion control; transport protocols: TCP/UDP r network services m routing; network protocols: IP/IPv6 r link and physical layers m multiple access; Ethernet, FDDI, hubs and bridges r multimedia networking m audio/video applications; network support r network security m security primitives; BAN logic, SSL r network management

8. 8 What Do You Need To Do? r Your prerequisites m algorithms: e.g. shortest path algorithms m programming: C/C++, or Java m basic concepts of operating systems r Your workload m Homework assignments programming assignments m 4 class tests (on Saturday) CT-1: 4 rd week CT-2: 7 th week CT-3: 9 th week CT-4: 13 th week No additional notices of CT will be given. If SAT is OFF then CT on Next Available Class.

9. 9 Course Overview: Part 1: Introduction (text: Chapter 1) r What is the Internet, What is a protocol? r Network edge, network core, network access r Physical media r Delay, loss in packet-switched networks r Protocol layers, service models r Internet backbones, NAPs and ISPs r A brief history of networking, Internet

10. 10 A top-down approach: We’ll cover networking top-down r end-system applications, end-end transport r network core: routing, hooking nets together r link-level protocols, e.g., Ethernet r other stuff: security, management, multimedia

11. 11 Course Overview: Part 2: Application Layer (text: Ch. 2) r Principles of application-layer protocols r The World Wide Web: HTTP r File transfer: FTP r Electronic mail in the Internet r The Internet's directory service: DNS r Socket programming PROGRAMMING ASSIGNMENT

12. 12 Course Overview: Part 3: Transport Layer (text Ch. 3) r Transport-layer services and principles r Multiplexing and demultiplexing applications r Connectionless transport: UDP r Principles of reliable of data transfer r TCP case study PROGRAMMING ASSIGNMENT r Principles of congestion control r TCP congestion control

13. 13 Course Overview: Part 4: Network Layer (text: Ch. 4) r Introduction and network service model r Routing principles PROGRAMMING ASSIGNMENT r Hierarchical routing r IP: the Internet Protocol r Routing in the Internet r What’s inside a router? r Mobile networks

14. 14 Course Overview: Part 5: Link Layer, LANs (text: Ch. 5) r Introduction, services r Error detection, correction r Multiple access protocols, LANs r LAN addresses, ARP r Ethernet r Hubs, bridges, switches r Wireless LANs: IEEE 802.11 r PPP: the Point-to-Point protocol r ATM networks

15. 15 Course Overview: Part 6: Network Security (text: Ch. 7) r What is network security? r Principles of cryptography r Authentication: Who are you? r Integrity r Key distribution, certification r Firewalls r Attacks, countermeasures r Case studies: secure e-mail, SSL, IPsec, 802.11 WEP

16. 16 Course Overview: Part 7: Network Management (text: Ch. 8) r What is Network Management? r Internet Network Management Framework, SNMP r ASN.1

17. 17 Course Overview: Part 8: Multimedia Networking (time permitting, text: Ch. 6) r Multimedia Networking Applications r Streaming Stored Audio and Video r Making the Best of the Best-Effort Service r Beyond Best Effort r Scheduling and Policing Mechanisms r Integrated Services r RSVP r Differentiated Services FINAL EXAM

18. 18 Outline  Administrative trivia’s  What is the Internet? m Nuts-and-bolds Description m Service Description m What is a Protocol?

19. 19 What’s the Internet: “nuts and bolts” view r millions of connected computing devices: hosts, end-systems m pc’s workstations, servers m PDA’s phones, toasters running network apps r communication links m fiber, copper, radio, satellite==Bandwidth (bps) r routers: forward packets (chunks) of data thru network local ISP company network regional ISP router workstation server mobile

20. 20 “Cool” internet appliances World’s smallest web server http://www-ccs.cs.umass.edu/~shri/iPic.html IP picture frame http://www.ceiva.com/ Web-enabled toaster+weather forecaster http://dancing-man.com/robin/toasty/

21. 21 What’s the Internet: “nuts and bolts” view r Route: series of communication links and routers r ISP: End system access the Internet thru ISP r Protocol: each end system, routers and other “pieces” of the Internet run protocol that controls communication. local ISP company network regional ISP router workstation server mobile

22. 22 What’s the Internet: “nuts and bolts” view r protocols: control sending, receiving of msgs m e.g., TCP, IP, HTTP, FTP, PPP r Internet: “network of networks” m loosely hierarchical m public Internet versus private intranet r Internet standards m RFC: Request for comments m IETF: Internet Engineering Task Force local ISP company network regional ISP router workstation server mobile

23. 23 What’s the Internet: a service view r communication infrastructure enables distributed applications: m WWW, email, games, e- commerce, database., voting, file (MP3) sharing r communication services provided: m connectionless m connection-oriented r cyberspace [Gibson]: “a consensual hallucination experienced daily by billions of operators, in every nation,...."

24. 24 What’s a protocol? human protocols: r “what’s the time?” r “I have a question” r introductions … specific msgs sent … specific actions taken when msgs received, or other events network protocols: r machines rather than humans r all communication activity in Internet governed by protocols

25. 25 What’s a protocol? r all communication activity in Internet governed by protocols A network protocol defines the format and the order of messages exchanged between two or more communicating entities, as well as the actions taken on the transmission and/or receipt of a message or other event.

26. 26 What’s a protocol? a human protocol and a computer network protocol: Q: Other human protocol? Hi Got the time? 2:00 TCP connection req. TCP connection reply. Get http://www.buet.ac.bd/index.htm time

27. 27 End of Class r Be Patient! r Lots of Real Life Scenario. r Ref: m K/R-1.1