Multimedia Tools and Applications

, Volume 45, Issue 1–3, pp 7–32 | Cite as

On the challenge and design of transport protocols for MMORPGs

  • Chen-Chi Wu
  • Kuan-Ta ChenEmail author
  • Chih-Ming Chen
  • Polly Huang
  • Chin-Laung Lei


Although MMORPGs are becoming increasingly popular as well as a highly profitable Internet business, there is still a fundamental design question: Which transport protocol should be used—TCP, UDP, or some other protocol? In this paper, we first evaluate whether TCP is suitable for MMORPGs, and then propose some novel transport strategies for this genre of games. Our analysis of a trace collected from a TCP-based MMORPG called ShenZhou Online indicates that TCP is unwieldy and inappropriate for MMORPGs. We find that the degraded network performance problems are due to the following characteristics of MMORPG traffic: 1) tiny packets, 2) a low packet rate, 3) application-limited traffic generation, and 4) bi-directional traffic. Since not all game packets require reliable transmission or in-order delivery, transmitting all packets with a strict delivery guarantee causes high delays and delay jitters. Therefore, our proposed transport strategies assign game packets with appropriate levels of transmission guarantee depending on the requirements of the packets’ contents. To compare the performance of our approach with that of existing transport protocols, we conduct network simulations with a real-life game trace from Angel’s Love. The results demonstrate that our strategies significantly reduce the end-to-end delay and delay jitter of packet delivery. Finally, we show that our strategies effectively raise satisfaction levels of the game players.


Content-based transport protocol Game traffic Network performance Online games Packet delivery User satisfaction 



The authors would like to thank the anonymous reviewers for their helpful comments. This work was supported in part by Taiwan Information Security Center (TWISC), National Science Council under the grants NSC97-2219-E-001-001 and NSC97-2219-E-011-006. It was also supported in part by the National Science Council of Taiwan under the grants NSC96-2628-E-001-027-MY3 and NSC97-2221-E-001-009.


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Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Chen-Chi Wu
    • 1
  • Kuan-Ta Chen
    • 2
    Email author
  • Chih-Ming Chen
    • 1
  • Polly Huang
    • 1
  • Chin-Laung Lei
    • 1
  1. 1.Department of Electrical EngineeringNational Taiwan UniversityTaipeiTaiwan
  2. 2.Institute of Information ScienceAcademia SinicaTaipeiTaiwan

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