1 / 46

CMPT 371

CMPT 371. Data Communications and Networking Course Organization. Data Communications + Networking. Wednesday 17:30 – 2 0:30 Textbook : Computer Networking (6 th Edition ) James F. Kurose, Keith W. Ross, Addison Wesley, 2005 Additional References: Computer Networks (4th Edition)

tracy
Download Presentation

CMPT 371

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CMPT 371 Data Communications and Networking Course Organization

  2. Data Communications + Networking • Wednesday 17:30 – 20:30 • Textbook: • Computer Networking (6th Edition) • James F. Kurose, Keith W. Ross, Addison Wesley, 2005 • Additional References: • Computer Networks (4th Edition) • Andrew S. Tanenbaum, Prentice Hall, 2003 • Data & Computer Communications (9th Edition) • William Stallings, Prentice Hall, 2007

  3. Class web-site • All the information discussed today and more can always be found on the class web-site • To find the class web site go to http://www.cs.sfu.ca/CourseCentral • Select Course Home pages • Select the Homepage for CMPT 371 • Course Central is also a useful link to abundant information useful to students taking a computing science course

  4. CMPT 371 Website

  5. My availability

  6. Your Teaching Assistant

  7. Exam Dates

  8. Evaluation

  9. Assignments • Four assignments • Each assignment is worth 7.5% of your course grade • Assignments are to be completed individually or in pairs • Problems similar to the assignments will appear on the final exam. • Solutions will be posted

  10. Quizzes • During every second Wednesday’s lecture, you will be asked to answer one or more questions based on material covered in the previous two weeks • You will be asked to write a concise paragraph of 25sentences or ideas, explaining a concept or method, or you will be asked to solve a problem • You will be given 20-25 minutes to answer.

  11. Final Exam • One 3 hour final examination • ~35% short answer problems • ~65% longer problems that utilize several important concepts and require integration of those concepts. • Some exam questions will be very similar to quiz and assignment questions. • A sample exam, including solutions, will be posted two weeks before the final

  12. Important Dates

  13. Assignments • At least two weeks before the due date the assignment will be posted on the website • Assignments must be completed individually or in pairs • Assignments will require you to combine and use many concepts and tools • Complete solutions to all assignments will be posted • Information of proper preparation of assignments and lab problems is available on the class website.

  14. Grading Information • Assignments should be: • submitted electronically using the submission server • Bonus points (10%) are available for submitting assignments more than 48 hours early • No late assignments will be accepted • Late assignments will receive a grade of 0 • Unofficial grades will be available on the course management system

  15. Readings and Notes

  16. Academic Honesty Read the policy

  17. CSIL Rules • Before you can use any of the computers in the CSIL if you have not read them before you should • Read the policies governing the use of CSIL • These policies can be found on the CMPT web site (see following slides) • When you log in you will be asked to confirm that you agree to abide by these policies

  18. CMPT 371 Data Communications and Networking Overview of Data Communications? What is a protocol?

  19. What is the internet • Internet is a network of many workstations, mobile devices, interconnecting devices (routers switches), servers (others?) • Internet is a collection of networks • Devices and networks use protocols to communicate by sending and receiving messages (information and instructions) • Protocols are described in RFC docs

  20. End systems: the network edge • An end system can be a source system, and/or a destination system at the edge of the Internet • End systems are connected by communication links • Guided media: Copper wire (coaxial, twisted pair), optical fibre • Unguided media: air (radio, microwave, IR …) • End systems are also referred to as hosts. They may host clients or servers • A client consumes a service • A server provides a service

  21. Examples of end systems • Mobile phone • Personal computer • Server supporting a service • Tablet • Others?

  22. Services the Internet provides • Communication between end systems • Communication supports many applications. Some applications include • WWW • Email, chat, voip • Commerce , data bases • Games, social media

  23. Data Communications • Many ways to transmit the information • Voice – in person, by telephone, internet, physically sending recorded media, wireless • Data – on paper disk or tape, vocally or digitally using LAN, WAN, internet, or wireless

  24. Data Communications • Want to send information from one location to another efficiently and accurately • Many transmission methods have independently evolved for particular types of data • Different transmission methods, used for voice, data, internet and video have converged in recent years

  25. Source Systems, Transmission • Source System: Includes data source and transmitting device which encodes data into electromagnetic signals suitable for transmission through the transmission medium • Example of Source Systems • Landline Telephone • Wireless Telephone, • Personal Computer:

  26. Examples • Landline Telephone: encodes/modulates voice or data into electrical signals to be carried through a line and a switching system • Wireless Telephone, Satellite or Radio: encodes/modulates voice or data into signals to be sent through an antenna • Personal Computer: encodes/modulates a data stream of binary bits to a form that can be efficiently carried through a computer network

  27. Transmission of Information • Information is sent from a source system to a destination system. • The information must be fed into the source system • The information must be encoded into a form the source system can send (usually into an electromagnetic signal) • The information travels through some transmission medium to the destination system • The destination system must be able to interpret (decode) the received signal • The decoded signal must be translated into a form that the operator of the destination system can understand

  28. Destination Systems • Destination System: Includes a receiver to intercept the transmitted electromagnetic signals from the transmission system and to decode/demodulate the those signals into a form appropriate for the destination device. • Landline Telephone: • Wireless Telephone, • Personal Computer

  29. Examples • Landline Telephone: decodes/demodulates signals carried through a line and a switching system into voice or data. • Wireless Telephone, Satellite or Radio: decodes/demodulates electromagnetic signals received by an antenna into voice or data. • Personal Computer: decodes/demodulates an electromagnetic signals from a computer network and reconstructs the information that was sent

  30. Simplified Communication Model Figure 1.1 Stallings (2003)

  31. Simplified Communications Model Figure 1.2 Stallings (2003)

  32. Data Communication Networking • The problem is more complex than point to point connection • Source and destination may be separated by large physical distances • Links may only be needed for a short time, dedicated links would be too expensive • Many devices, any of which may be the source or destination at a given time. • Multiple pairs of source and destination may wish to communicate through the same medium at the same time

  33. Data Communication Networking • These problems are addressed using networking protocols • All devices communicate via a net of connections • Efficiency and accuracy is maintained using protocols • What is a protocol?

  34. a human protocol and a computer network protocol: TCP connection response Get http://www.awl.com/kurose-ross Got the time? 2:00 <file> time What’s a protocol? Hi TCP connection req Hi

  35. Why a Network • The number of stations is large, it is not possible to have dedicated connections to all other end systems • The distance between two stations may be long enough that the transmission media cannot carry the signal from the source to the receiver without introducing many errors, going through intermediate devices will fix this problem • Worldwide connectivity is desired

  36. Station Interconnection: 1 • The number of stations is large. • Direct connection between all stations is not practical n(n-1)/2 connections are needed • Connection using a shared bus limited by distance (long paths with loss of signal due to attenuations) bus can carry information, lacks redundancy (any failure of link destroys connectivity), and allows only 1 message at a time to travel at a time Station 1 Station 2 Station 3

  37. Station 1 Station 2 Station 3 Station 6 Station 4 Station 5 Station 7 Station Interconnection: 2 • The number of stations is large. • Connection in a tree routes too much traffic through the root. • Connection through a Partially Connected Network distributes traffic and provides redundancy. Also provides a mechanism for repeating signals to enable long distance propagation

  38. Station Interconnection: 3 • Connection through a Partially Connected Network provides redundancy and intermediate stations along the path to act as repeaters Station 2 Station 3 Station 1 Station 12 Station 14 Station 13 Station 7 Station 10 Station 6 Station 9 Station 6 Station 4 Station 5 Station 11

  39. Wide Area Networks • A WAN covers a large geographical area • A WAN often uses common carrier or public right-of-ways • A WAN uses internal nodes to move data through network

  40. Local Area Networks • A LAN interconnects a variety of devices in a small area: Building or campus scope • LAN is usually owned/controlled and managed by one organization. • Most common types of LANs are • Ethernet • ATM. • Wireless

More Related