Computer Networks
How the Internet actually moves bits.
The Internet & Layered Architecture
The Internet is an impossibly complex system made tractable by one elegant idea: layered abstraction that separates policy from mechanism at every level.
The Link Layer & Ethernet
The link layer is where bits on a wire become reliable hops between neighbors — framing, addressing, and arbitration are the invisible contract every Ethernet frame silently enforces.
The Network Layer & IP Routing
The network layer is the global addressing and routing fabric that makes the internet one logical network out of millions of heterogeneous physical ones.
The Transport Layer: TCP & UDP
TCP and UDP are the two workhorses of the internet's transport layer — one promises every byte arrives in order, the other gets out of the way and lets you move fast.
Congestion Control
Congestion control is the distributed algorithm that prevents the internet from collapsing under its own traffic — TCP's self-imposed braking system that makes global fairness emerge from purely local decisions.
The Application Layer: DNS & HTTP
From typing a URL to getting a webpage: master DNS resolution, HTTP evolution, and the application-layer protocols that power the entire web.
Network Security: TLS & Beyond
TLS, PKI, and the full network-security stack — from wire-level attacks to the cryptographic handshake that protects every HTTPS connection you've ever made.
Modern Networking
From radio waves to globally distributed software — how modern networking transcends the wire.