How can you scale your game networking code for multiplayer games?

1 What is game networking?

Game networking is the process of exchanging data between different devices or programs involved in a game. This data can include player input, game state, physics, graphics, sound, and more. Game networking can be divided into two main categories: client-server and peer-to-peer. In client-server networking, one device or program acts as the central authority that manages the game logic and data, while the others connect to it as clients. In peer-to-peer networking, each device or program communicates directly with each other, without a central authority. Each approach has its advantages and disadvantages, depending on the game genre, design, and requirements.

2 How to choose a network protocol?

A network protocol is a set of rules and standards that define how data is formatted, transmitted, and received over a network. There are many network protocols available, but the most common ones for game networking are TCP and UDP. TCP stands for Transmission Control Protocol, and it ensures that data is delivered reliably and in order. UDP stands for User Datagram Protocol, and it allows data to be sent quickly and without confirmation. TCP is more suitable for games that require consistency and accuracy, such as turn-based or strategy games. UDP is more suitable for games that prioritize speed and responsiveness, such as action or racing games.

3 How to optimize network bandwidth?

Network bandwidth is a limited and valuable resource, especially for multiplayer games, as it is the amount of data that can be transferred over a network in a given time. To optimize network bandwidth, one must minimize the amount and frequency of data sent and received. Compression and encoding can help reduce the size of data packets, while delta compression allows you to send only the changes in data instead of the whole data. Interpolation and prediction can be used to smooth out the movement and animation of objects, instead of sending every position update. Relevance and interest management can filter out data that is not important or visible to each player, such as objects that are far away or behind walls. Finally, batching and aggregation can group multiple data packets into one, reducing the overhead of network headers and acknowledgments.

4 How to handle network latency?

Network latency is an inevitable and unpredictable delay between sending and receiving data over a network, which can affect the gameplay and user experience of multiplayer games. To handle this, game networking code should be designed with certain considerations and techniques. Client-side prediction can simulate the game logic and input on the client device before receiving confirmation from the server or other peers, reducing the perceived lag and improving responsiveness. Server-side reconciliation can prevent cheating and ensure consistency of the game, while lag compensation adjusts the game state based on each player's latency. Network smoothing can also be used to avoid abrupt changes in the game state due to latency, improving the visual and auditory quality of the game.

5 How to test and debug network code?

Testing and debugging network code can be difficult and time-consuming, as it involves multiple devices, programs, and scenarios. To make the task easier, you should use some tools and methods, such as a network simulator or emulator to mimic different network conditions, a network analyzer or monitor to capture and inspect data packets, and a network logger or profiler to record and measure performance. This will help you test how your game networking code performs under various situations, identify errors or anomalies, diagnose inefficiencies, and optimize and improve your game networking code.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?