The course is built on fifteen questions that every protocol has to answer. Each part answers one. Every part page shows this grid with its own question highlighted, so you always know where you are.
Row | Parts | What it covers |
|---|---|---|
Getting bits across | 0–3 | What a protocol is, when a receiver samples, how it finds message boundaries, and how two sides agree a word moved |
Moving transactions | 4–7 | How much may be in flight, what a transaction asks for, how many can overlap, and in what order results appear |
Sharing and surviving | 8–11 | Who gets a shared resource, why systems hang, how errors are caught and repaired, and how links start up |
System concerns | 12–15 | Power, shared state across caches, security, and proving the whole thing correct |
Two threads matter most. The sizing thread runs through handshakes, credits, concurrency and replay: each time, a buffer or a window must cover a round trip, and the same bandwidth × latency reasoning answers it. The agreement thread runs through handshakes, ordering, deadlock and coherence: each time, two or more agents must reach the same conclusion from what they can see.
The credit loop (Part 4). Both hold something until an answer comes back, so both must cover bandwidth × round-trip time or the sender stalls.