Online games are a fundamental part of the entertainment industry but the current IP infrastructure does not satisfactorily fulfill the needs of these services. The novel networking architecture Named Data Networking (NDN) inherently supports network-level multicast and packet-level security and thereby introduces promising features for online games. In this paper, we propose an NDN-based approach to synchronize game state in a server cluster, a task necessary to allow multiple players in large numbers to play in the same game world. The proposed Quadtree Synchronization Protocol applies NDN’s data-centric nature to decouple the game world from the game servers hosting it. This means that requesting changes of a specific game world region becomes possible without knowing which game server is responsible for the requested region. We use a hierarchic game world structure when requesting data that allows the network to forward requests to the responsible game server without directly addressing it. This region-based naming scheme decouples world regions from servers which eases the management of the game server cluster and allows easier recovery after server failures. In addition, this decoupling allows exchanging information about a geographical region, such as a game world, without knowledge of the other participants changing the world. Such a region-based synchronization mode is not possible to implement with existing protocols. However, it allows building distributed systems that do not require a central server to work. Besides architectural benefits, network emulations show that our protocol increases the efficiency of data transport by utilizing network-level multicast. Our proposed approach can keep up with current protocols which can be used for inter-server game state synchronization.

在线游戏是娱乐业的基本组成部分，但是当前的IP基础结构不能令人满意地满足这些服务的需求。名为数据网络（NDN）的新型网络体系结构固有地支持网络级多播和数据包级安全性，从而为在线游戏引入了有希望的功能。在本文中，我们提出了一种基于NDN的方法来同步服务器群集中的游戏状态，这项任务是允许多个玩家在同一游戏世界中进行游戏所必需的。拟议的四叉树同步协议利用NDN以数据为中心的性质将游戏世界与托管它的游戏服务器分离。这意味着可以在不知道哪个游戏服务器负责所请求区域的情况下请求更改特定游戏世界区域。当请求数据时，我们使用分层的游戏世界结构，该数据允许网络将请求转发到负责的游戏服务器而无需直接寻址。这种基于区域的命名方案使世界区域与服务器脱钩，从而简化了游戏服务器群集的管理，并使服务器出现故障后更易于恢复。另外，这种解耦允许交换关于地理区域的信息，例如游戏世界，而无需其他参与者改变世界的知识。使用现有协议无法实现这种基于区域的同步模式。但是，它允许构建不需要中央服务器即可工作的分布式系统。除了体系结构的好处，网络仿真还表明，我们的协议通过利用网络级多播提高了数据传输的效率。我们提出的方法可以跟上当前可用于服务器间游戏状态同步的协议。