Academia Sinica  |  Institute of Information Science  |  Multimedia Networking and Systems Laboratory
An Empirical Evaluation of TCP Performance in Online Games
(NOTE: Sheng-Wei Chen is also known as Kuan-Ta Chen.)

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 objective 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 inappropriate for MMORPGs. This is due to four distinctive characteristics of MMORPG traffic: 1) tiny packets, 2) low packet rate, 3) application-limited traffic generation, and 4) bidirectional traffic. We show that because TCP was originally 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. Furthermore, 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.

An extended version of this paper: On the Challenge and Design of Transport Protocols for MMORPGs

Kuan-Ta Chen, Chun-Ying Huang, Polly Huang and Chin-Laung Lei, "An Empirical Evaluation of TCP Performance in Online Games," In Proceedings of ACM SIGCHI ACE`06, Los Angeles, USA, Jun 2006.

  AUTHOR     = {Kuan-Ta Chen and Chun-Ying Huang and Polly Huang and Chin-Laung Lei},
  TITLE      = {An Empirical Evaluation of {TCP} Performance in Online Games},
  BOOKTITLE  = {Proceedings of ACM SIGCHI ACE`06},
  MONTH      = {Jun},
  YEAR       = {2006},
  ADDRESS    = {Los Angeles, USA},
  X_TAG      = {og}