## Structure

All references to "ass" in the following are courtesy of StrangeZak.

### Prereqs

- TCP/UDP
    - Packets and ordering
- Sockets
    - Port forwarding, firewalls - context for why you might do NAT punching
    - hey ive heard of this thing called "web sockets"
        - tcp over tcp, baby
    - Blocking vs. non-blocking sockets
- Peer-to-peer / network topology
    - why peer to peer is ass
    - NAT punching: STUN/ICE/TURN
        - Types of NATs (carrier-grade vs. normal)
    - WebRTC
    - UPNP (auto port forwarding) (possibly an aside?)
        - security problems
        - please do not
- Handshakes / authentication

### Games

- Code structuring for games
    - the way every game handles you know replicating eneitites to other clients is very different so you have ot pick the one that you think is least ass
    - they are all ass
- Prediction / rollback
    - Older model: every input is sent to the server, server sends state to clients
    - Newer model: local game is simulated independently, corrected by the server as it goes (prediction and rollback)
    - How some games might do this
        - Unreal: go over all connections, iterate all actors, see if actor is relevant, delta, bunch, send
            - typical of big shooter games - you want to be able to control relevancy of data per connection (e.g. what is in view)
        - Simple 2D game: send the whole state
- Server / client authority
- RPCs

### Audio / video streaming

- Packet framing (deltas / key frames / error correction)
    - I, P, and B-frames (for video)

### Collaborative editing

- CRDTs...? Operational transforms?

## Possible applications of real-time networking

- Multiplayer games
- Collaborative editing
- Real-time communication (audio/video)

## Useful practice projects

These would all need to be written and vetted by the community. We're not going to find good examples of this lying around.

- Basic multiplayer game with rollback
- Online voice chat
- Figma-like?

## Links

- I, P, and B-frames: https://ottverse.com/i-p-b-frames-idr-keyframes-differences-usecases/
- https://discord.com/channels/239737791225790464/727209479602438265/973342326644703262
- Overwatch Gameplay Architecture and Netcode: https://www.youtube.com/watch?v=zrIY0eIyqmI
    - Zak says: Best explanation of modern techniques by far. Ignore the game architecture part.
- https://www.deconstructconf.com/2019/ayla-myers-multiplayer-game-networking-the-brute-force-approach
- https://www.ggpo.net/
- Opus spec: https://datatracker.ietf.org/doc/html/rfc6716
-