1 / 32

Network Game Research – Introduction and Counter-strike Analysis

Network Game Research – Introduction and Counter-strike Analysis. Mark Claypool. Outline. Overview of Network Games Net Games Conference Research Issues Analysis Counter-strike Our Results. Why Study Games?. Rapidly increasing in popularity Forrester Research: 18 million on-line in 2001

Roberta
Télécharger la présentation

Network Game Research – Introduction and Counter-strike Analysis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Network Game Research –Introduction and Counter-strike Analysis Mark Claypool

  2. Outline • Overview of Network Games • Net Games Conference • Research Issues • Analysis Counter-strike • Our Results

  3. Why Study Games? • Rapidly increasing in popularity • Forrester Research: 18 million on-line in 2001 • Consoles on-line • Playstation 2 on-line (9/2002) • Xbox Live (12/2002) • Cell phones • Doom port (Nokia) • Design networks to better accommodate traffic

  4. Game Types • First Person Shooters • Doom, Quake, Counter-strike, … • Massive Multi-Player Online Role Playing • Everquest, Earth and Beyond, … • Real-Time Strategy • Warcraft, Starcraft … • Other • Misc – not any genre above • Example: Diablo2, Racing, … • Non-networked • Example: Thief • Multiplayer, but relaxed real time • Example: Chess, Bridge

  5. Net-Games - Workshop on Network and System Support for Games • First was 2002 in Braunschweig, Germany • http://wwwmc.tm.uni-karlsruhe.de/netgames2002/ • Second is in Redwood City, California • http://confman.eecs.umich.edu/netgames2003/ • Sponsored by: • ACM • Electronic Arts • Microsoft

  6. Net-Games Program Committee • Sugih Jamin, University of Michigan (Chair) • Mostafa Ammar, Georgia Institute of Technology • Grenville Armitage, Swinburne University of Technology • John Buchanan, Electronic Arts • Jon Crowcroft, University of Cambridge • Christophe Diot, Sprintlabs • Wu-chang Feng, Oregon Health and Science University • Carsten Griwodz, University of Oslo • Jim Kurose, UMass at Amherst • John Laird, University of Michigan • Brian Neil Levine, UMass at Amherst • Martin Mauve, University of Mannheim • Hiroyuki Morikawa, University of Tokyo • Dan Rubenstein, Columbia University • Srinivasan Seshan, Carnegie Mellon University • Wilson Yuen, City University of Hong Kong • Lars Wolf, TU Braunschweig

  7. Net-Games Topics • Multi-player game architectures and platforms • Prevention and detection of cheating • Games on mobile and resource-scarce devices • AI and techniques for latency hiding • Modeling, usage studies, and characterization • Enabling protocols for networked games • Systems support for authentication and accounting • Put research issues here

  8. Wu-chang Feng, Francis Chang, Wu-chi Feng, Jonathan Walpole Provisioning On-line Games: A Traffic Analysis of a Busy Counter-Strike Server

  9. Goal • Understand the resource requirements of a popular on-line FPS (first-person shooter) game

  10. Why FPS? • While there are other game types … • Gaming traffic dominated by first-person shooter genre (FPS) [McCreary00]

  11. Networked FPS lineage Doom Unreal Unreal Tournament Doom II Quake + QuakeWorld variants + Team Fortress + Capture the Flag Unreal Tournament 2003 + America's Army: Operations Quake II + Soldier of Fortune + Heretic II Quake III Arena + Medal of Honor Allied Assault + Return to Castle Wolfenstein + Soldier of Fortune 2 + Jedi Knight II Half-Life + Counter-Strike + Day of Defeat + Urban Terror + Team Fortress Classic + Team Fortress 2 8 of top 10 games derived from one of two lineages Doom III

  12. About the game... • Half-Life modification • Two squads of players competing in rounds lasting several minutes • Rounds played on maps that are rotated over time • Each server supports up to 32 players

  13. What is Counter-strike (CS)?

  14. What is Counter-strike (CS)?

  15. What is Counter-strike (CS)?

  16. About the game... • Centralized server implementation • Clients update server with actions from players • Server maintains global information and determines game state • Server broadcasts results to each client • Sources of network traffic • Real-time action and coordinate information • Broadcast in-game text messaging • Broadcast in-game voice messaging • Customized spray images from players • Customized sounds and entire maps from server

  17. Why CS?

  18. Why CS?

  19. The Trace • cs.mshmro.com (129.95.50.147) • Dedicated 1.8GHz Pentium 4 Linux server • OC-3 • 70,000+ unique players (WonIDs) over last 4 months • One week in duration 4/11 – 4/18 • 500 million packets • 16,000+ sessions from 5800+ different players

  20. A week in the life...

  21. Variance time plot Less variance < 50ms Remains to 30 min Decreases above 30 min (Normalized to base interval of 10ms)

  22. Digging deeper • Periodic server bursts every 50ms • Game must support high interactivity • Game logic requires predictable updates to perform lag compensation Interval size=10ms Interval size=50ms

  23. Digging deeper • Low utilization every 30 minutes • Server configured to change maps every 30 minutes • Traffic evenly pegged otherwise.... Interval size=1sec Interval size=30min

  24. Finding the source of predictability • Games must be fair across all mediums (i.e. 56kers) • Aggregate predictability due to “saturation of the narrowest last-mile link”

  25. Packet sizes • Supporting narrow last-mile links with a high degree of interactivity requires small packets • Clients send small single updates • Servers aggregate and broadcast larger global updates

  26. Implications • Routers, firewalls, etc. must be designed to handle large bursts at millisecond levels • Game requirements do not allow for loss or delay (lag) • Should not be provisioned assuming a large average packet size [Partridge98] • If there are buffers anywhere, they must... • Use ECN (no, doesn’t use TCP) • Be short (i.e. not have a bandwidth-delay product of buffering) • Employ an AQM that works with short queues • Rate-based not Queue-based

  27. Implications • ISPs, game services • Must examine “lookup” utilization in addition to link utilization • Concentrated deployments of game servers may be problematic • Large server farms in a single co-lo • America's Army, UT2K3, Xbox

  28. On-going work • Other pieces in the provisioning puzzle • Aggregate player populations • Geographic distributions of players over time (IP2Geo) • Impact on route and packet classification caching • Other FPS games • HL-based: Day of Defeat • UT-based: Unreal Tournament 2003, America's Army • Quake-based: Medal of Honor: Allied Assault • Results apply across other FPS games and corroborated by other studies

  29. Future work • Games as passive measurement infrastructure • Only widespread application with continuous in-band ping information being delivered (measurement for free) • “Ping times” of all clients broadcast to all other clients every 2-3 seconds • 20,000+ servers, millions of clients • Games as active measurement infrastructure • Thriving FPS mod community and tools • Server modifications [Armitage01] • Other game types

  30. Some Net-Games Research at WPI • Mark Claypool, David LaPoint, and Josh Winslow. “Network Analysis of Counter-strike and Starcraft”, In Proceedings of the 22nd IEEE International Performance, Computing, and Communications Conference (IPCCC), Phoenix, Arizona, USA, April 2003. Online at: http://www.cs.wpi.edu/~claypool/papers/net-game/ • Compared FPS (Counter-strike) with RTS (Starcraft) • Smaller number of traces • Controlled set of users

  31. Our Results • Confirms packet sizes for Counter-strike • Starcraft results: • Packets smaller • Linear increase with number of players • Starcraft traffic much smoother (bandwidth usage) than Counter-strike • Counter-strike bursty during ‘fire-fights’ • (PEDS talk later)

  32. Network Game Research –Introduction and Counter-strike Analaysis Mark Claypool

More Related