Transport and Network Layer

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reading · we frame, you read MIT or the canonical taught · we author, no canonical fits ↺ spirals back to earlier lessons

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Complete Network Fundamentals and Application Layer first.

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Prerequisites

Network Fundamentals and Application Layer not yet

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reading · 30 min + ~197 min canonical

The Network Layer: IP Addressing, Subnets, and CIDR

The link layer from the last course only gets a frame across one hop — machine to the next switch. But the internet is billions of machines separated by dozens of hops across netw…

primary Kurose & Ross lecture videos — Transport and Network sections (YouTube)

preview →

reading · 30 min + ~197 min canonical L1

Routing: How Packets Find Their Way (and NAT, DHCP, ARP)

You have an addressed packet (last lesson) and you want it to reach a server on the other side of the planet. No single machine knows the whole path. Instead, dozens of routers ea…

primary Kurose & Ross lecture videos — Transport and Network sections (YouTube)

after L1 locked

reading · 35 min + ~197 min canonical L1

TCP: Building a Reliable Stream Over an Unreliable Network

The network layer you just learned is best-effort: it forwards packets and shrugs. Packets get lost, duplicated, reordered, corrupted, and delayed, and IP promises nothing about a…

primary Kurose & Ross lecture videos — Transport and Network sections (YouTube)

after L2 locked

reading · 30 min + ~197 min canonical L1

Congestion Control and TCP vs UDP: Sharing the Network, Choosing the Trade-off

The last lesson showed how TCP makes your connection reliable. But your connection isn't alone — it shares the internet's links and routers with millions of others, and if every s…

primary Kurose & Ross lecture videos — Transport and Network sections (YouTube)

after L3 locked

reading · 30 min + ~197 min canonical L1

CDNs, Load Balancing, and the Edge: Networking as Architecture

This lesson closes the networking quarter by turning everything you've learned into architecture — the network techniques that make real systems fast and scalable. Two ideas domin…

primary Kurose & Ross lecture videos — Transport and Network sections (YouTube)

after L4 locked

exercise reading · 15 min L1

Exercises: Easy (Warm-up)

- [ ] Subnetting exercises: Given 192.168.1.0/24, create 4 subnets — Calculate ranges, broadcast, usable hosts - [ ] Trace a packet path using traceroute — Identify hops, RTT, net…

after L5 locked

exercise reading · 30 min L1

Exercises: Medium (Core)

- [ ] Implement a reliable transport protocol over UDP in C — Add sequence numbers, ACKs, retransmission - [ ] Build a simple load balancer in Ruby — Round-robin distribution acro…

after L6 locked

exercise reading · 45 min L1

Exercises: Hard (Stretch)

- [ ] Implement a simple BGP route table in Ruby — Parse route announcements, longest prefix matching - [ ] Build a NAT simulator in C — Rewrite source IP/port, maintain translati…

after L7 locked

exercise reading · 60 min L1

Mini-Project

- [ ] Build a peer-to-peer file sharing tool in C — Discover peers on LAN via UDP broadcast, request file chunks via TCP, reassemble; handle peer disconnection

after L8 locked

L10

project reading · 480 min L1

Project: Reliable UDP in C

Build a reliable transport protocol on top of UDP sockets. Implement sequence numbers, ACKs, retransmission with exponential backoff, and a sliding window. Transfer a file reliabl…

after L9 locked

L11

project reading · 300 min L1

Project: Load Balancer in Ruby

Build a TCP load balancer that accepts connections on a port and distributes them across backend servers using round-robin, least-connections, or weighted algorithms. Health-check…

after L10 locked

L12

project reading · 300 min L1

Project: WebSocket Echo Server in Ruby

Implement the WebSocket handshake (HTTP Upgrade), frame parsing/encoding, ping/pong, and message echo. Connect with a browser or websocat. No gems (use TCPServer directly). (~5 ho…

after L11 locked

L13

assessment reading · 63 min L1

Self-Assessment: Transport and Network Layer

- [ ] Explain TCP's three-way handshake (SYN, SYN-ACK, ACK). Why is it necessary? - [ ] What is TCP flow control? Explain the sliding window mechanism. - [ ] What is TCP congestio…

after L12 locked

L14

assessment reading · 60 min L1

Quarter 7 Gate Check: Computer Networks

- [ ] Course 7.1 knowledge check passed - [ ] Course 7.2 knowledge check passed - [ ] HTTP/1.1 Server capstone completed

after L13 locked

14 lessons. Read in order; spiral back when you need to. By the end you'll have used the core ideas twice — once on the abstract, once on something you'll meet at work next week.