Conference Paper

An empirical evaluation of TCP performance in online games

DOI: 10.1145/1178823.1178830 Conference: Proceedings of the International Conference on Advances in Computer Entertainment Technology, ACE 2006, Hollywood, California, USA, June 14-16, 2006
Source: DBLP


A fundamental design question to ask in the development of a network game is—Which transport protocol should be used—TCP, UDP, or some other protocols? Seeking an ob- jective answer to the choice of communication protocol for MMORPGs, we assess whether TCP, a popular choice, is suitable for MMORPGs based on empirical evidence. To the best of our knowledge, this work is the first evaluation of transport protocol performance using real-life game traces. We analyze a 1, 356-million-packet trace from ShenZhou Online, a TCP-based, commercial, mid-sized MMORPG. Our analysis indicates that TCP is unwieldy and inappropri- ate for MMORPGs. This is due to four distinctive charac- teristics of MMORPG traffic: 1) tiny packets, 2) low packet rate, 3) application-limited traffic generation, and 4) bi- directional traffic. We show that because TCP was origi- nally designed for unidirectional and network-limited bulk data transfers, it cannot adapt well to MMORPG traffic. In particular, the window-based congestion control and the fast retransmit algorithm for loss recovery are ineffective. Fur- thermore, TCP is overkill, as not every game packet needs to be transmitted in a reliably and orderly manner. We also show that the degraded network performance did impact users' willingness to continue a game. Finally, we discuss guidelines in designing transport protocols for online games.

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Available from: Kuan-Ta Chen
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    • "Network traffic of MMORPGs has been a target of a number of studies which are summarized in survey papers [3] [12]. Chen et al. and Wu et al. [2] [5] evaluate performance of TCP for online games in general and discuss whether TCP is in fact a suitable protocol for MMORPGs. They identify some network performance degradation problems derived from the traffic characteristics of this game genre: tiny packets, low packet rate, application-limited traffic generation, and bidirectional traffic. "
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    ABSTRACT: ManyMassivelyMultiplayer Online Role-Playing Games (MMORPGs) use TCP flows for communication between the server and the game clients. The utilization of TCP, which was not initially designed for (soft) real-time services, has many implications for the competing traffic flows. In this paper we present a series of studies which explore the competition between MMORPG and other traffic flows. For that aim, we first extend a source-based traffic model, based on player’s activities during the day, to also incorporate the impact of the number of players sharing a server (server population) on network traffic. Based on real traffic traces, we statisticallymodel the influence of the variation of the server’s player population on the network traffic, ending on the action categories (i.e., types of in-game player behaviour). Using the developed traffic model we prove that while server population only modifies specific action categories, this effect is significant enough to be observed on the overall traffic.We find that TCP Vegas is a good option for competing flows in order not to throttle the MMORPG flows and that TCP SACK is more respectful with game flows than other TCP variants, namely, Tahoe, Reno, and New Reno. Other tests show that MMORPG flows do not significantly reduce their sending window size when competing against UDP flows. Additionally, we study the effect of RTT unfairness between MMORPG flows, showing that it is less important than in the case of network-limited TCP flows.
    Full-text · Article · Jan 2014 · International Journal of Computer Games Technology
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    • ", video streaming [13], online gaming [6], and data centers [7], to name a few. However, until recently, there has been marginal attention on investigating the BGP over TCP behavior. "
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    ABSTRACT: Although there have been a plethora of studies on TCP performance in supporting of various applications, relatively little is known about the interaction between TCP and BGP, which is a specific application running on top of TCP. This paper investigates BGP's slow route propagation by analyzing packet traces collected from a large ISP and Route Views Oregon collector. In particular we focus on the prolonged periods of BGP routing table transfers and examine in detail the interplay between TCP and BGP. In addition to the problems reported in previous literature, this study reveals a number of new TCP transport problems, that collectively induce significant delays. Furthermore, we develop a tool, named T-DAT, that can be deployed together with BGP data collectors to infer various factors behind the observed delay, including BGP's sending and receiving behavior, TCP's parameter settings, TCP's flow and congestion control, and network path limitation. Identifying these delay contributing factors makes an important step for ISPs and router vendors to diagnose and improve the BGP performance.
    Full-text · Conference Paper · Jan 2012
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    • "We have designed the PGTP protocol based on these recommendations. • Lightweight and low overhead: It has been shown that 98% of game packets have a payload of less than 32 bytes [3]. Thus, the overhead incurred by a transport protocol in managing the connection should be proportionally small compared to the payload. "
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    ABSTRACT: Applications on the smartphones are able to capitalize on the increasingly advanced hardware to provide a user experience reasonably impressive. However, the advancement of these applications are hindered battery lifetime of the smartphones. The battery technologies have a relatively low growth rate. Applications like mobile multiplayer games are especially power hungry as they maximize the use of the network, display and CPU resources. The PGTP, presented in this paper is aware of both the transport requirement of these multiplayer mobile games and the limitation posed by battery resource. PGTP dynamically controls the transport based on the criticality of game state and the network state to save energy at the wireless network interface (WNIC) level with almost no degradation to the quality of the game play.
    Full-text · Conference Paper · Mar 2011
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