• Course Overview
• What is Networking?
• What is interesting about Networks?
  • Hardware
  • Protocols
  • Software
  • Performance
• Clients and servers
• Homework assignment
• Class Evaluation

• TA: Xiaowei Sun, xsun@hawaii.edu
• MWF 12:30-11:20 in Watanabe 420
• textbook: Communication Networks, by Walrand (Second Edition only)
• midterm, final (each 20% of the grade)
• 3 projects (20% of the grade)
• homeworks (20% of the grade), handed out on Mondays, due the following Monday.
• pop quizzes (20% of the grade)
• Office hours MW 3-4 in POST 303B.
• http://www.ics.hawaii.edu/~esb/fall1998.ics451/

• learn fundamental design principles of computer networks,
• study in detail networks of practical importance, including:
  • the Internet and TCP/IP
  • ethernet
  • ATM
• write computer programs to implement networked applications and simple networking protocols.

• Basics
• Physical Layer: Media, Transmission
• Data-Link Layer (LANs): Ethernet, FDDI, ATM
• Internet Layer: IP
• Transport Layer: TCP, UDP
• Presentation Layer: Encoding, Encryption
• Networking Management: SNMP

• Error Correction
• Routing
• Probability and Queueing Theory

A computer network is a digital hardware and software system that enables a collection of computers to communicate.

"Computer Networks are able to carry many different types of data and support a wide range of applications"

Networking is the engineering, science and art of designing computer networks.

Notes:

• What is networking

• Answer 1: networking means getting to know people so that I can get a job when I graduate.

• Answer 2: What is a computer network?

• Engineering, science and art: engineering because we need to make tradeoffs among competing requirements, science because to do so we need to study and characterize a complex system, and art because sometimes the most aesthetically pleasing designs are also the best.

Although this course will not focus on designing networking hardware, the design and performance analysis of networks and protocols require a high-level understanding of network hardware.

We will look at a variety of point-to-point links and shared media.

Notes:

Networking protocols are agreeements about how independent computers communicate given a physical way to exchange data.

We will study in some detail both the main LAN protocols and the main of the TCP/IP suite (the Internet protocols).

We will also review protocol structuring principles such as the OSI 7-layer model.

Throughout the course, we will be considering issues of performance, including:

• Cost and benefit of different operations
• Limitations imposed by number of bits
• Fairness
• Error Recovery

Projects in this course will focus on providing practice with standard APIs and in implementing standard protocols.

A client is a program that requests a service; a server is a program that provides a service. Clients and servers normally run on different machines, and use computer networks to communicate.

Notes:

A client on one machine can send a request to a server on a different machine. The server will generally respond appropriately.

This is a very generic model, and can encompass all sort of interactions. For example:

• WWW (clients: Netscape, Internet Explorer, Lynx, etc.. Servers: Netscape, Apache, etc)
• Telnet
• FTP
• Network Time Protocol (NTP)
• Network File Server (NFS)
• ...

Notes:

A sender in a communication sends the data; a receiver receives the data. The receiver may send acknowledgements to indicate it has received the data.

In a Client-Server system, the client is first a sender, then a receiver.