CSCE 515: Computer Network Programming

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CSCE 515Computer Network Programming

• Chin-Tser Huang
• huangct_at_cse.sc.edu
• University of South Carolina

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About Me

• Chin-Tser Huang
• Ph.D. in Computer Sciences, 2003,
• University of Texas at Austin
• My second year with USC
• Research in network security, network protocol
  design and verification, distributed systems
• My web page can be found at http//www.cse.sc.edu/
  huangct

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About the Course

• A course focusing on programming aspects of
  computer networks
• Course will be divided into two parallel themes
• Network architecture and protocols
• Network programming issues in Java

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Course Information Online

• http//www.cse.sc.edu/huangct/CSCE515S05/index.ht
  m
• Look for information about
• Topics and schedule
• Projects and homeworks
• Grading rules
• Useful links

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Why You Should Take This Course

• Network applications are becoming more and more
  important to our life
• You want to have a clear understanding of network
  architecture and TCP/IP suite
• You also want to have good ability in
  network-based software design and implementation
• You have chances to implement the skills learned
  in the classes

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Your Best Strategy

• Come to every lecture
• Keep yourself exposed to articles related to
  network protocols and network programming
• Finish each assigned reading before coming to
  class
• Do not wait till last minute to prepare for exam
  or work on project
• Enjoy the fun!

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What Is Going On

• when your computer receive a message from your
  partner?

?
Internet
m
x
y
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What Is Going On

• First, your partner needs to construct the
  message and send it to the network

m
Internet
x
y
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What Is Going On

• Then, routers in the Internet collaborate to
  forward the message toward your computer

m
Internet
x
y
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What Is Going On

• Finally, your computer needs to determine which
  application should receive the message

telnet
?
ftp
m
browser
Internet
x
y
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Other Issues Beyond This

• Multicast or broadcast?
• Proxy?
• Security features?

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Network Protocols

• Abstractions of communication between two
  processes over a network
• Define message formats
• Define legitimate sequence of messages
• Take care of physical details of different
  network hardware and machines
• Separate tasks in complex communication networks
• For example, FTP and ARP

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Protocol Layering

• Many problems need to be solved in a
  communication network
• These problems can be divided into smaller sets
  and different protocols are designed for each set
  of problem
• Protocols can be organized into layers to keep
  them easy to manage

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Properties of Protocol Layer

• Functions of each layer are independent of
  functions of other layers
• Thus each layer is like a module and can be
  developed independently
• Each layer builds on services provided by lower
  layers
• Thus no need to worry about details of lower
  layers -- transparent to this layer

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Protocol Stack OSI Model
Application
Presentation
Session
Transport
Network
Data link
Physical
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Communicating End Hosts
Host
Host
Application
Application
Presentation
Presentation
Session
Session
Transport
Transport
Router
Network
Network
Network
Data link
Data link
Data link
Physical
Physical
Physical
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Next Class

• Seven layers in OSI reference model
• Corresponding Internet architecture
• Application programming interface (API)
• Read TI Ch. 1, JNP Ch. 1