Method and apparatus for supporting real-time multi-user distributed applications

Abstract

The present invention addresses the shortcoming of the prior art by providing a network support mechanism that is transparent to real-time multi-user distributed applications. In particular, the proposed invention is well suited for the type of online multi-player games in which a fair order of player actions is critical to the outcome. Without fairness support, remote players often receive much delayed data to act on, and their actions cannot compete in time with other players. The present invention proposes a network support mechanism, called Sync-VPN, for real time multi-user distributed applications such as multi-player online games. The approach assumes a client/server application model, where the server is responsible for coordinating state updates based on action messages sent by the clients. The approach addresses three desired features: predictable packet service, state update fairness, and player action fairness. It builds on top of bandwidth guaranteed VPN service to ensure predictable packet delay and loss characteristics. It uses a Sync-out mechanism to synchronize the delivery of state updates to all players in order for them to react to the same update fairly Its Sync-in mechanism processes action messages from all players in a fair order based on their real-time occurrence. Sync-VPN employees a round trip time estimation algorithm that is essential to both Sync-out and Sync-in mechanisms in estimating message latency. It also proposes three Sync-in algorithms that dictate a trade-off between added delay and improved fairness.

Dependencies are inferred from the claim text.