Network Programming (CIS-3152) Home Page

This is the home page for Peter Chapin's Network Programming course for the Fall 2025 semester. Here you will find electronic versions of class handouts, homework assignments, lecture slides, and links to references. If you are a student taking Network Programming, consider bookmarking this page.

The course syllabus gives an overview of the course and its content, lists course resources, and describes the grading policy and related issues.
The homework submission area and grade book are on Canvas but all other course resources are here.
Here are instructions on how to set up the development environment we will be using for this course.
For running servers on Lemuria, please use the ports allocated to you.
I have prepared a short document on using Git to help you get familiar with the system. Some of the samples I will use in this course are on GitHub.
I've prepared some general information on submitting assignments.
My home page contains other resources of potential interest.

Lecture Topics

2025-08-26. Course introduction and overview. Started describing the daytime client.
2025-08-28. Finished describing the daytime client program.
2025-09-02. Described the daytime server program.
2025-09-04. Described concurrent servers using forked processes.
2025-09-09. Demonstrated "vibe coding" by adding additional error handling to the echo client program. Finished discussing the concurrent echo server with demonstration.
2025-09-11. Demonstrated the threaded version of the echo server. Discussed the potential for deadlock in the echo client/server.
2025-09-16. Demonstrated the IPv6 version of the daytime client/server. Discussed the getaddrinfo() function.
2025-09-18. Gave an overview of UDP programming and the DNS system.
2025-09-23. More discussion about UDP programming in the context of a simple DNS client.
2025-09-25. Introduced character sets.
2025-09-30. Discussed Unicode in more detail: encoding, BOM, combining characters.
2025-10-02. Discussed Homework #2/3 on TFTP.
2025-10-07. No class (Vacation).
2025-10-09. No class (Vacation).
2025-10-14. Demonstrated Unicode samples. Demonstration of Claude Code and JetBrains Junie. Review of bit manipulation operations in C.
2025-10-16. Introduced SMTP and gave a tour of the existing MailFlux code base.

Slides

Weeks 1-5	Weeks 6-9	Weeks 10-14
Introduction Daytime Client and Server Concurrent TCP Servers TCP Details, Part 1 TCP Details, Part 2 UDP Details Programming UDP DNS (see RFC-1035) Trivial FTP (see RFC-1350) Character Sets ASCII, ISO-646, ISO-8859, C0 and C1, ISO-2022 Unicode Consortium, Unicode Technical Site UTF-32, UTF-16, UTF-8, BOM	SMTP. See also RFC-5321. MailFlux. An SMTP server for experts.	...

Homework

Homework #1 (20 pts) Daytime Client/Server. Due: 2025-09-10.
Homework #2/3 (30 pts) Trivial FTP. Implement the receive_file function for IPv6 in this skeletal TFTP client: tftpclient.c, tftpclient.h

Samples

The daytime client/server in C demonstrates the basics of TCP client/server programming using the Sockets API on Unix.
The echo client/server in C demonstrates how to write a concurrent server. Two versions are provided: one that uses individual child processes to handle each client connection and one that uses threads.
The IPv6 version of the daytime client/server demonstrates the basics of IPv6 programming using the Sockets API.
The getaddrinfo() function can be used to look up IP addresses and port numbers. This demonstration program illustrates its use.
A sample Unicode text file using UTF-8 and UTF-16 encoding.
Some short programs that illustrate a few issues with the handling of extended (non-ASCII) character sets: Java, C++.

Resources/Articles

I've written a C tutorial that you might find useful for reviewing certain concepts from C.
RFC Index. Here you can look up any RFC or browse the RFC index itself. This sample implements the daytime protocol.
This Quick Reference for Tshark may be useful for getting started with this complex and powerful tool.
This document describes how to set up PuTTY and how to set up SSH tunnels using PuTTY.

Labs

In the past this was a lab course. For practical reasons related to the structuring of our overall CIS offerings, the lab was removed from this course. However, the labs are still interesting and can serve as a source of extended examples and as the basis for some assignments.

The lab set is summarized in the lab summary document, along with links to specific lab handouts and supporting code samples.