Csc5113c Page

You learn fast. You learn that sequence numbers without crypto are just polite suggestions. You learn that "congestion" is often just malice. And you learn that tcpdump is the difference between an A and a sleepless incomplete. Ask any CSC5113C alumnus about ~/lab4/attacks/ . They’ll go quiet.

CSC5113C does something crueler—and far more educational. It forces you to implement the protocols, then immediately break them. csc5113c

In CSC5113C, the network isn't a series of tubes. It's a gladiator arena. Most networking courses teach you the OSI model, TCP state diagrams, and BGP routing. You memorize port numbers. You calculate checksums. You yawn. You learn fast

My code was perfect. The math was solid. But my throughput looked like a flatline. After three hours of blaming the compiler, the kernel headers, and my own existence, I finally enabled promiscuous mode on the NIC. That’s when I saw it. And you learn that tcpdump is the difference

There is a moment in every Computer Science graduate course where the textbook stops making sense and reality kicks in. For me, that moment came at 2:00 AM in the networking lab, watching Wireshark scroll by like the green code from The Matrix .

I was debugging a "simple" TCP congestion control algorithm for my CSC5113C project. The assignment was straightforward: modify the Linux kernel’s TCP stack to improve throughput over high-latency links. Straightforward, until it wasn't.

One student famously found a delayed SQL injection spread across 47 fragmented ICMP echo requests. The professor didn’t even know that was possible until the student presented it. "Don't trust the wire. Don't trust the endpoint. Don't trust your textbook." This isn't paranoia. It’s the course’s core thesis. The Internet was built on trust. Modern networks survive on verification.