(Redes de Computadores) Who? How? When? Why? What?

Transcription

1 Computer Networking (Redes de Computadores) Who? How? When? Why? What?

2 Who's the teacher?

3 Who's the teacher? PhD. Mª del Carmen Romero Ternero Theory, problems & laboratory classes! Office: G1.51, Tutorships: CBA

4 How will we study the subject? How is the evaluation? How can I join the English group?

5 Basic bibliography: Computer Networking: A topdown approach, 5th edition. James F. Kurose, Keith W. Ross. ISBN-13: (c) 2009 Addison- Wesley/Pearson. How will we study the subject? Master classes Problems resolution Pre-lab study works In-lab experimental works Tests & questions on paper / webct Misc assignments

6 How is the evaluation? Continuous evaluation: T&P: 20% tests & questions in classroom + 80% theory+problems control (in January) LabsC: Attendance and academic progress Labs LabExam (in January) Final Grade (FG): 80% T&P + 20% LabsC YOU PASS if (FG>=5 && T&P>=4 && LabsC>=4) If you fail one part and pass another, it's kept until 3rd convocatory (December 2014)

7 What does laboratory academic progress mean? It is compulsory to do pre-lab in an individual way before each laboratory session: Study and take a look theory and problems Take a look the bibliography Search in Internet Review previous experimental study Tutorships

8 What does laboratory academic progress mean? It is compulsory to attend, show interest and answer the teacher s questions: Ask for help to the teacher Take a look theory and problems I don't understand I didn't have enough time to finish... Finish it at home

9 What does happen if I don t show laboratory academic progress? You don t pass the laboratory part in continuous assessment. You don t do the final laboratory session to be evaluated in continuous assessment. Have I to stop attending laboratory if I already know I can t pass the laboratory part in continuous assessment? We don t recommend it to you. If you don t pass the continuous assessment, you must do a laboratory exam in official call. This exam will have questions about prelabs and experimental studies.

10 How is the evaluation? Official evaluation: T&P: theory+problems official exam LabsF: lab official exam: pass or fail. Final Grade (FG): 80% T&P + 20% LabsC or 100% T&P and LabsF pass. YOU PASS if (FG>=5 && T&P>=4 && Labs>=4) If you fail one part and pass another, it's kept until 3rd convocatory (December 2014)

11 How can I join the English group? You have to request it at ETSII Secretary Fill in the form here: DEADLINE: BEFORE October 11th!

12 When are the classes?

13 When are the classes? Monday 12:30-14:30 Theory master I0.10 Thursday 10:30-12:30 Problem I0.10 G1.31 starting Lab1 on Oct 3rd scheduling in web and WebCT

14 Why should I join the English group?

15 Why should I join the English group? Same content, labs & exams as Spanish Redes de Computadores I won't evaluate your English level but you may practise Reduced groups Only one teacher for everything Progress control & tutorships more personal...

16 What will I learn?

17 Goals To know the basics of Computer Networking, by focusing in TCP/IP architecture (Internet), the fundamental protocols and the basic operation for the required devices to work properly.

18 Goals

19 Goals

20 Using Wireshark sniffer

21 Commands: netstat

22 Commands: ping & traceroute

23 Build a Java client for an online app

24 ...and hack your colleagues passwords

25 Using actual equipment (a small Intranet)

26 Unit 1: TCP/IP network stack application: supporting network applications FTP, SMTP, HTTP transport: process-process data transfer TCP, UDP network: routing of datagrams from source to destination IP, routing protocols link: data transfer between neighboring network elements Ethernet, (WiFi), PPP application transport network link physical physical: bits on the wire Introduction 1-26

27 Unit 1: Throughput R s < R c What is average end-end throughput? R s bits/sec R c bits/sec R s > R c What is average end-end throughput? R s bits/sec R c bits/sec bottleneck link link on end-end path that constrains end-end throughput Introduction 1-27

28 Unit 2: TCP client-server interaction

29 Unit 3: multiprocess web server P1 P4 P5 P6 P2 P1P3 SP: 5775 DP: 80 S IP: B D IP:C client IP: A SP: 9157 DP: 80 server IP: C SP: 9157 DP: 80 client IP: B S IP: A S IP: B D IP:C SP = Source port # DP = Destination port # S IP = Source IP address D IP = Destination IP address No problem if two client process use the same source port D IP:C No problem if two client process use the same source IP Transport Layer 3 29

30 Unit 3: reliable data transfer Example 1. Tx sends only a PDU with UD and doesn t send the next until the transmission is sucessful. Rx only sends ACK control PDU. PDU X ACK X PCI dtranspdu dtransack PDU 1 ACK 1 Time_out PDU 1 PDU 1 Lost PDU PDU 2 Time ACK 2 PDU 3 ACK 3 Time_out ACK 1 PDU 2 PDU 2 X wrong PDU ACK 2 Tx Without errors Rx Tx With errors Rx Transport Layer 3 30

31 Unit 4: IP address, routers, /22 RT Router Network Next hop Interface /22 E / /22 E /22 Network / /22 E /22 E0 E1 E2 Network / / /22 note To know which is the right path to the destination IP addr, an and logic operation has to be done with the netmask of a particular RT entry and the destination IP addr. If the network identifier matches the one in the RT then this is the route to take. Network / / /22 RT Host /22 Network Next hop Interface IP_PDU to Network identifier Directed Broadcast /22 E / E Network Layer 4 31

32 Unit 5: MAC address, switch, hub

33 Slides provide support for master classes but they must not replace your own notes

34 Scheduling

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