Part 10 answers: What if bits go wrong?
Every real channel flips bits now and then. A protocol has to decide how to notice (parity, CRC, ECC), what to do about it (correct, ask again, poison, report), and at which layer, without breaking ordering or hiding a failing link.
This part covers error models, parity, Hamming distance, CRC, ECC, forward error correction, error responses, poison, ACK/NAK, sequence numbers, replay buffers, go-back-N and selective repeat, idempotency, link-level versus end-to-end protection, error reporting, recovery, interface protection and reliability budgets.
Choose between parity, CRC, ECC and FEC for a given channel.
Size a replay buffer and a sequence-number field.
Turn a bit error rate into a replay rate and an undetected-error rate.
Answer each in your head before opening it. If two or more feel shaky, revisit Part 9: Deadlock and Liveness first.
Mutual exclusion, hold and wait, no preemption, and circular wait. Break any one and deadlock cannot happen.
If responses could be refused, a response stuck behind a full requester can block the resources other requests need to complete: a message-dependent deadlock.
In deadlock nothing moves. In livelock things keep moving (retries, handshakes) but no useful work completes.
# | Lesson | Level | Status |
|---|---|---|---|
10.1 | F · Foundation | Ready | |
10.2 | F · Foundation | Ready | |
10.3 | W · Working | Ready | |
10.4 | W · Working | Ready | |
10.5 | W · Working | Ready | |
10.6 | S · Senior | Ready | |
10.7 | W · Working | Ready | |
10.8 | S · Senior | Ready | |
10.9 | W · Working | Ready | |
10.10 | W · Working | Ready | |
10.11 | S · Senior | Ready | |
10.12 | S · Senior | Ready | |
10.13 | P · Principal | Ready | |
10.14 | S · Senior | Ready | |
10.15 | S · Senior | Ready | |
10.16 | S · Senior | Ready | |
10.17 | P · Principal | Ready | |
10.18 | P · Principal | Ready | |
— | all levels | Ready | |
— | all levels | Ready |
Every lesson in this part is ready. Work through them in order: each one sets up the problem the next one solves.
This course teaches why protocols are designed the way they are. These lessons show how to build or sign off the same ideas, so this part links to them instead of repeating them.