1. GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent Weishuai Yang Nael Abu-Ghazaleh {wyang,nael}@cs.binghamton.edu

2. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 2 Peer-to-Peer

3. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 3 P2P Simulation Emphases Looking up Downloading 1 5 4 2 6 3 1 5 4 2 6 3

4. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 4 BitTorrent (BT) Scenario HTTP GET Tracker Peer 1 (Leecher) Peer 2 (Leecher) Peer 3 (Seed)

5. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 5 BitTorrent (BT) Scenario Tracker Peer 1 (Leecher) Peer 2 (Leecher) Peer 3 (Seed).torrent file

6. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 6 BitTorrent (BT) Scenario Tracker Peer 1 (Leecher) Peer 2 (Leecher) Peer 3 (Seed) Announce Tracker

7. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 7 BitTorrent (BT) Scenario Tracker Peer 1 (Leecher) Peer 2 (Leecher) Peer 3 (Seed) Peer List

8. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 8 BitTorrent (BT) Scenario Tracker Peer 1 (Leecher) Peer 2 (Leecher) Peer 3 (Seed) Hand Shaking

9. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 9 BT Algorithms Piece Selection –Strict Priority –Rarest First –Random First –End Game Mode Peer Selection (server side and peer side) Rechoking, optimistic unchoking, and anti- snubbing Pipeline request

10. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 10 GPS: General P2P Simulator http://www.cs.binghamton.edu/~wyang/gps Modeling downloading process Message level simulation Graphical

11. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 11 GPS Architecture

12. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 12 Framework Components Core Components –Simulation Engine –Topology –Protocols –Agents (includes Peers & Servers) –Documents –Keywords Special Components –GUI –Asynchronous Logging

13. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 13 BTSim Components BTProtocol BTTrackers and BTPeers BTDocuments BTSessions, BTSockets and BTConnections BTAlgorithms

14. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 14 Accounting for Network & Protocol Effect Peer Based Bandwidth(PBB) Flow Model –Peer End Allocation Dynamic Link-Level Network Bandwidth (DLNB) Flow Model –Bandwidth Allocation Algorithm TCP Based Flow (TBF) Model –Macro Formula: BW=MSS*C/(RTT*P^(1/2))

15. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 15 Macro Model Simulation Validation MSS=536 bytes RTT=1.7ms C=1.22 p=0.1%

16. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 16 Link Based Flow Model Simulation Validation

17. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 17 Scalability Study Peers randomly attached to non-transit nodes Documents with rankings are randomly stored at Peers User actions are randomly initiated every 50 seconds NodesPeersDocs(500M)Downloads 116844 2643216 325212864 41054512256

18. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 18 Scalability Study cont. (DLNB based)

19. 9/29/2005 GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent 19 Questions? Thank You! Weishuai Yang wyang@cs.binghamton.edu