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Knowledge Update Course
for Secondary School Computer and IT Teachers
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Computer Networking and Data Communication
Internet Applications and E-commerce Concept
Jasper Wong
email: icjwong@polyu.edu.hk
Industrial Centre
The Hong Kong Polytechnic University
July, 2003
July, 2003
Computer Networking & Data Communication – Internet Applications
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Internet Applications
• World Wide Web
– Client-server interaction
– Hypertext transfer protocol
– Browser architecture
• Electronic mail representation and transfer
– Electronic mailbox and address
– Electronic mail message format
– The simple mail transfer protocol
• File transfer
– The file transfer protocol
– File types and transfer modes
• Basic e-commerce concept
July, 2003
Computer Networking & Data Communication – Internet Applications
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Client-Server Computing
• Network
– Operates at application’s request
• Applications
– What to send
– When to send
– Where to send
– the interpretation of bits
•
Internets
– Provide a general communication infrastructure
– Two application programs must participate in any
communication, one initiates communication and the
other accept it.
July, 2003
Computer Networking & Data Communication – Internet Applications
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Client-Server Computing
•
Internet protocols provide
– Facilities for reliable data transfer
– Mechanism for host communication
• Applications
– Use internet protocols to interact other applications
• Information display format
• Define symbolic names to identify both the physical and
abstract resources available on an internet
– e.g. for physical resources: computers, I/O devices
– e.g. for abstract resources: files, electronic mail &
databases
– Provide user-level services
July, 2003
Computer Networking & Data Communication – Internet Applications
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Client-Server Computing
Client Characteristics:
• Arbitrary application program, temporary remote
access client and performs other computation locally
• Invoked directly by user, and