Weitere ähnliche Inhalte Mehr von Academia Sinica (20) Kürzlich hochgeladen (20) Quantifying the Effect of Content-based Transport Strategies for Online Role Playing Games1. Quantifying the Effect of Content‐based Transport
MNe
t
Strategies for Online Role Playing Games
Chih-Ming Chen1, Kuan-Ta Chen2, and Polly Huang1
M 1National Taiwan University 2Academia Sinica
Lab
Motivation Transport Strategies Performance Evaluation
Protocol MMORPGs Average end‐to‐end transmission latencies
Message Type In-Order Delivery Reliability
TCP World of Warcraft, Lineage I/II, Guild Wars, Ragnarok
Move Client Traffic Server Traffic
Online, Anarchy Online, Angel’s Love
600
UDP EverQuest, City of Heroes, Star Wars Galaxies, Ultima Attack √ TCP P_MRO TCP P_MRO
180 200 220 240 260 280 300
UDP P_MR UDP P_MR
Online, Final Fantasy XI Talk √ √
500
Mean delay (ms)
Mean delay (ms)
SCTP P_M SCTP P_M
TCP/UDP Dark Age of Camelot
Multi‐streaming
400
There is no consensus on protocols for MMORPGs • Put different message types into separate streams
300
• e.g., move message, attack message, talk message
MMORPGs requirements
200
Optional ordering
Low transmission latency • Certain message types do not require in‐order transport 20 40 60 80 100 120 140 20 40 60 80 100 120 140
No unexpected “lags” Client # Client #
• e.g., move message, attack message
Optional reliability Average end‐to‐end delay jitters (standard deviation of delays)
Objective • Certain message types do not require reliability
• e.g., move message
Client Traffic Server Traffic
250
600
TCP P_MRO TCP P_MRO
Quantify the effect of content‐based transport strategies Strategy Multi-Streaming Optional Optional
UDP P_MR UDP P_MR
200
500
SCTP P_M SCTP P_M
Mean jitter (ms)
Mean jitter (ms)
Evaluate existing transport protocols Ordering Reliability
400
150
MRO √
300
• TCP, UDP, DCCP, SCTP
100
MR √ √
200
Propose and evaluate three content‐based transport strategies
50
100
M √ √ √
usingnetwork simulations
0
0
20 40 60 80 100 120 140 20 40 60 80 100 120 140
Real-Life Game Traces
Real-Life
Client # Client #
Simulation Setup
Users’ action trace of Angel’s Love Trace‐driven network simulation using ns‐2 simulator Summary
Fishbone topology
• 1 game server Improvement of Delay Improvement of Delay Jitter
• 2 network routers Client Traffic Server Traffic Client Traffic Server Traffic
100
100
100
100
70 Clients 70 Clients 70 Clients 70 Clients
• n game clients 140 Clients
75
140 Clients 140 Clients 79 140 Clients
80
80
80
80
73
69 69
• m cross traffic pairs 55
60
60
60
60
Score
Score
Score
Score
45 46
Client Node (CN)
40
40
40
40
33
28
CNi+2 . . . CN CN2 . . . CN Traffic Node (TN)
20
20
20
20
8 10
n i 0
2 0 0
2
0 1 1 0 1
5 5
CNi+1 CN1
0
0
0
0
P_MRO P_MR P_M P_MRO P_MR P_M P_MRO P_MR P_M P_MRO P_MR P_M
Protocol Protocol Protocol Protocol
Client to Server Server to Client
TNj+1 TN1 Server Protocol Delay Jitter Delay Jitter
TNj+2 . . . TNm TN2
TN
. . . j TCP NA NA NA NA
SCTP ≈ ≈ ★ ★
DCCP (TCP-like) ★★★★ ★★★★ ★★★ ★★★
Bandwidth & propagation delay DCCP (TFRC) ☆ ☆ ☆ ☆
Link Bandwidth Propagation Delay UDP ★★★★ ★★★★ ★★★★ ★★★★
Server <--> Router 600 Kbps 70 ms PMRO ≈ ≈ ★ ★
Router <--> Router 600 Kbps 70 ms PMR ≈ ≈ ★★ ★★
Router <--> Client 64 ~ 128 Kbps 70 ms PM ★★★ ★★★ ★★★ ★★
User ID Actions (M: Move, A: Attack, T: Talk) Description: NA denotes incomparable, ≈ denotes similar, ☆ denotes worse, ★ denotes better, ★ ★ denotes
Router <--> Traffic Node 64 ~ 128 Kbps 70 ms
10159 MMMMMMMMMMMMMAMMAMMMMMMAMMMMMMMMMM much better, ★ ★ ★ denotes good, ★ ★ ★ ★ denotes very good, and ★ ★ ★ ★ denotes excellent.
11 pairs cross traffic with 500 Kbps sending rate
12454 MMAAMAMMMMMAAMAMAMAMAMAMAMAMAMAMAMAMA
16728 MMMMMMMMMMMMMMMMMMMMMMAMMTTTTTTTTTTTT Multimedia Networking and Systems Lab
Institute of Information Science, Academia Sinica
http://mmnet.iis.sinica.edu.tw