Transcript Class Notes #1

COMP 2330 (3 units)
Data Communications and Networking
Name: Dr. Joseph NG
Office: R707 (Sir Run Run Shaw Building)
Phone: 2339-7864
Email: [email protected]
HomePage: http://www.comp.hkbu.edu.hk/~jng
Name: Dr. Hon Wah Tam
Office: R713 (Sir Run Run Shaw Building)
Phone: 2339-7093
Email: [email protected]
TA Name: Mr. Calvin Kin Cheung Hui
Email: [email protected]
Subject Outline
Objectives
• To introduce the major concepts of data communication and computer
networks;
• To provide an introduction to network programming;
• Network functions and protocols with reference to the ISO Reference
Model and the existing local area networks will be studied.
Textbook
• Stallings, William, Data and Computer Communications, 5th Edition,
Prentice Hall, 1997.
Assessment
• Continuous assessment (30%)
• Examination (70%)
Subject Outline (continue)
Passing grade and Grade Distribution (Guidelines)
• A (10 +/- 5%)
• B (50 +/- 10%)
• C, D, F (40 +/- 15%)
• Average of this class should be either B- or C+.
• To pass this subject, the final exam should be higher than 30.
• To get the “A” grade, the overall score should be higher than 70.
• Each person, each semester can have one supplementary exam.
• The highest grade for supplementary exam is “D”.
A warning for those copy cats
• Whoever get caught in copying homework and other assignments, the
instructor has the right to penalize his/her grade when necessary.
Computer Networks --- An Overview
• Computer Network
– A computer network is a communication system that allows computers to
exchange information with each other in a meaningful way.
– Computer networks may link computers that are all of the same type
(homogeneous networks), or they may link computers of several different
types (heterogeneous networks)
– Size of the network: same room, same floor, same building, same campus,
city, region/country, or across international boundaries.
– Three abbreviations computer networks:
• LAN: Local area network offers high speed communication (10Mbps)
between computers within a limited area.
• WAN: Wide area network can vary considerably. Usually covers the
whole country. WAN may be provided by post, telephone and
telegraph organizations. WAN also includes radio and satellite.
• MAN: Metropolitan area network is not yet well-defined. They offer
a simple, fast way to link different organizations for the exchange of
information with a similar degree of flexibility to that provided by
LANs.
The International Standards Organization Reference Model of
Open System Interconnection (ISO OSI model)
Host A
1
Application
Host B
Message
interfaces
2
Presentation
Message
interfaces
3
Session
Message
Subnet
4
Transport
Message
Boundary
5
Network
Packet
6
Data Link
Frame
7
Physical
Bit
Applications on Computer Networks
• Sharing Resources
– Computing power (main-frames, super-computers)
– Databases (Air-line reservation, Banking accounts)
– Archives (wuarchive, ftp.cica.indiana.edu, ftp.cs.cuhk.hk, ftp.cdrom.com)
– Printers (line printer, laser printer, image printer)
– Scanners
– File server
– Program libraries (X-windows, g++ lib, Motif)
– Expensive software (CASE tools, CAD/CAM)
• Data Communication
– File Transfer Protocol (FTP upload/download)
– News Server (notesfile, Bulletin board)
– Email
– Voice mail, video mail, facsimile (FAX)
– World Wide Web Server
– talk, IRC, ICQ