Terminology

This page gives a quick overview of network terms and also links to page that is related to it.

Authority

The peer that has authority of a game object owns it and have the ability to update the state of an object.

Client

A client is a peer connected to a server.

Control Data

The input and action data that each peer send to the other peers to tell them what he is doing. Is sent at a high freq.

Determinism

If the same State and control data for a frame always lead to the same result state the game is deterministic.

Events

Notifactions about transient occurrences. For example a gun is fired, someone died. Often sent as RPC's.

Extrapolation

Using the past history of a state to guess it's future state. If we have the last two positions of a object we can use them to make a line and guess where the object will be some time in the future.

Host

The peer that setup and start a game is called the host.

Interpolation

With two or more states at certain times we can calculate the state of a time in between these two.

Lag

When one notice a delay between the action and response in a multiplayer game. The feedback of the game fail to keep up with what the player expect. Related to high latency or failure to hide the existence of the latency by the game.

Latency

The time from when peer A sends a message to peer B receives it. In milliseconds.

Peer

One of the computers that is part of the multiplayer game.

Peer-to-peer

All the peers can communicate with each other.

Ping

The round-trip time (send and get a reply) from peer A to peer B. In milliseconds.

Prediction

Extrapolating the properties of an entity based on historical data and guesses about the future.

Replication

To sync a object from the authority to the other peers. 'Replicating a object' means causing it to be created and updated on a remote peer. A 'replicated object' is one whose state is kept approximate in sync between peers.

RPC / Remote procedure call

A way to call remote functions on one or more peers.

Server

The peer that makes all the important decisions is the server. Often it has authority over most objects in the game.

State

The parts of a object that need to be sent over to the other peers for them to show an approximation of the object. The thing that matter is the most current state.

Tick

A single update of the game world on a server is called a tick. The number of times the server update the world per second per second is the servers tickrate.