The Effect of TCP Variants on the Coexistence of MMORPG and Best-Effort Traffic
This addresses network performance issues for MMORPG users and network administrators, but it is incremental as it builds on existing TCP research.
The study investigated how TCP variants affect the coexistence of MMORPG and best-effort traffic, finding that TCP Vegas maintains a constant rate and prevents packet loss and high queuing delays, while TCP SACK and New Reno cause higher packet loss and delays, and smaller buffers reduce overall delay for MMORPGs.
We study TCP flows coexistence between Massive Multiplayer Online Role Playing Games (MMORPGs) and other TCP applications, by taking World of Warcraft (WoW) and a file transfer application based on File Transfer Protocol (FTP) as an example. Our focus is on the effects of the sender buffer size and FTP cross-traffic on the queuing delay experienced by the (MMORPG) game traffic. A network scenario corresponding to a real life situation in an ADSL access network has been simulated by using NS2. Three TCP variants, namely TCP SACK, TCP New Reno, and TCP Vegas, have been considered for cross-traffic. The results show that TCP Vegas is able to maintain a constant rate while competing with the game traffic, since it prevents packet loss and high queuing delays by not increasing the sender window size. TCP SACK and TCP New Reno, on the other hand, tend to continuously increase the sender window size, thus potentially allowing higher packet loss and causing undesired delays for the game traffic. In terms of buffer size, we have established that smaller buffers are better for MMORPG applications, while larger buffers contribute to a higher overall delay.