GPS: A General Peer-to-Peer Simulator and its Use for Modeling BitTorrent

1
GPS A General Peer-to-Peer Simulator and its Use
for Modeling BitTorrent

• Weishuai Yang
• Nael Abu-Ghazaleh
• wyang,nael_at_cs.binghamton.edu

2
Peer-to-Peer
3
P2P Simulation Emphases

• Looking up
• Downloading

1
2
6
5
3
4
4
BitTorrent (BT) Scenario
Tracker
HTTP GET
Peer 1(Leecher)
Peer 3(Seed)
Peer 2(Leecher)
5
BitTorrent (BT) Scenario
Tracker
.torrent file
Peer 1(Leecher)
Peer 3(Seed)
Peer 2(Leecher)
6
BitTorrent (BT) Scenario
Tracker
Announce Tracker
Peer 1(Leecher)
Peer 3(Seed)
Peer 2(Leecher)
7
BitTorrent (BT) Scenario
Tracker
Peer List
Peer 1(Leecher)
Peer 3(Seed)
Peer 2(Leecher)
8
BitTorrent (BT) Scenario
Tracker
Hand Shaking
Peer 1(Leecher)
Peer 3(Seed)
Peer 2(Leecher)
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
GPS General P2P Simulator

• Modeling downloading process
• Message level simulation
• Graphical

http//www.cs.binghamton.edu/wyang/gps
11
GPS Architecture
12
Framework Components

• Core Components
• Simulation Engine
• Topology
• Protocols
• Agents (includes Peers Servers)
• Documents
• Keywords
• Special Components
• GUI
• Asynchronous Logging

13
BTSim Components

• BTProtocol
• BTTrackers and BTPeers
• BTDocuments
• BTSessions, BTSockets and BTConnections
• BTAlgorithms

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 BWMSSC/(RTTP(1/2))

15
Macro Model Simulation Validation
MSS536 bytes RTT1.7msC1.22p0.1
16
Link Based Flow Model Simulation Validation
17
Scalability Study
Nodes Peers Docs(500M) Downloads
1 16 8 4 4
2 64 32 16 16
3 252 128 64 64
4 1054 512 256 256

• Peers randomly attached to non-transit nodes
• Documents with rankings are randomly stored at
  Peers
• User actions are randomly initiated every 50
  seconds

18
Scalability Study cont.
(DLNB based)
19
Questions?
Thank You!
Weishuai Yang wyang_at_cs.binghamton.edu