NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
1 Vattay
Interacting Network Elements: Chaos and Congestion Propagation
Gábor Vattay
Department of Physics of Complex Systems[1]
Eötvös University, Budapest, Hungary
and
Ericsson Telecommunication Hungary
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
2 Vattay
Outline
• The more complex word of ad-hoc, mobile networks and p2p applications
• Complex system approach
• Pattern formation in traffic, congestion
propagation
• Chaotic and non-linear dynamics
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
3 Vattay
The new more complex word …
• P2P traffic vs. web traffic hosts are more equal, core/access distinction is not that important
• Mobile, ad-hoc: bandwidth is fully utilized
• Strong interaction
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
4 Vattay
Complexity and non-linear research
• Complexity research deals with large number of strongly interacting systems, (IST-FET-Complexity)
• Chaos, fractals/scaling pattern formation, granular and vehicular traffic…
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
5 Vattay
Congestion propagation
Fukuda &Takayasu 1999
Router-to-router congestion propagation
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
7 Vattay
A congestion propagation model
Vattay, Steger, Vaderna 2003
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
8 Vattay
Simulation results: 10 queues, 10 TCP
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
9 Vattay
50 queues, 1 TCP/queuedeffect propagation
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
10 Vattay
10 queues, 5 TCP/queue, web traffic
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
11 Vattay
1TCP/que with initial delay t_dt_d [ms] timespan 0-4000 sec
0 0.01 0.1 0.2 0.3 0.4 0.5 0.6
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
12 Vattay
Measuring the speed of propagation: center of mass velocity
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
13 Vattay
td[ms] Site/sec
0 -0.154421
.1 -0.140778
.2 -0.141784
.3 -0.120683
.4 -0.059653
.5 -0.103517
.6 -0.032555
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
14 Vattay
What causes congestion propagation?
1 TCP/queue (ns2) Our fluid model using Baccelli-Hong (2002)
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
15 Vattay
Only one assumption is needed: packet loss is more likely for a joining TCP
flow at the router
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
16 Vattay
Chaos
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
17 Vattay
Simplest network model
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
18 Vattay
Periodicity
Veres & Boda INFOCOM 2000
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
19 Vattay
Chaos
Veres & Boda INFOCOM 2000
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
20 Vattay
Ljapunov properties
Veres & Boda INFOCOM 2000
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
21 Vattay
Veres & Boda INFOCOM 2000
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
22 Vattay
3 TCPs with different round trip times
Vattay, Marodi, Steger 2002
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
23 Vattay
Congestion window evolution
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
24 Vattay
Poincarè surface of section
Symbols: 1,2,3
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
25 Vattay
Fractal dimension of the attractor
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
26 Vattay
Symbol sequence probability
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
27 Vattay
Topological entropy
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
28 Vattay
Basin of attraction
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
29 Vattay
2 TCPs surface of section
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
30 Vattay
Topological entropy
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
31 Vattay
Interaction of flows
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
32 Vattay
Interacting traffic flows
• Traffic flows crossing the same bottleneck can inherit scaling properties from each other
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
33 Vattay
Kenesi, Molnár, Veres, Vattay SIGCOMM 2000
NeXtworking’03 June 23-25,2003, Chania, Crete, GreeceThe First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
34 Vattay
Mode locking structure of adaptation
Buchta & Vattay 2003
TCP
Background (UDP)
Bandwidth C