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Interacting Network Elements: Chaos and Congestion Propagation. Gábor Vattay Department of Physics of Complex Systems [1] Eötvös University, Budapest, Hungary and Ericsson Telecommunication Hungary. Outline. The more complex word of ad-hoc, mobile networks and p2p applications
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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, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
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, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
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, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
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, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Congestion propagation NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Router-to-router congestion propagation Fukuda &Takayasu 1999
A congestion propagation model Vattay, Steger, Vaderna 2003 NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Simulation results: 10 queues, 10 TCP NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
50 queues, 1 TCP/queuedeffect propagation NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
10 queues, 5 TCP/queue, web traffic NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
t_d [ms] timespan 0-4000 sec 0 0.01 0.1 0.2 0.3 0.4 0.5 0.6 1TCP/que with initial delay t_d NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Measuring the speed of propagation: center of mass velocity NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
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, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
What causes congestion propagation? 1 TCP/queue (ns2) Our fluid model using Baccelli-Hong (2002) NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
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, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Chaos NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Simplest network model NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Periodicity Veres & Boda INFOCOM 2000 NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Chaos Veres & Boda INFOCOM 2000 NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Ljapunov properties Veres & Boda INFOCOM 2000 NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Veres & Boda INFOCOM 2000 NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
3 TCPs with different round trip times Vattay, Marodi, Steger 2002 NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Congestion window evolution NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Poincarè surface of section Symbols: 1,2,3 NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Fractal dimension of the attractor NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Symbol sequence probability NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Topological entropy NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Basin of attraction NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
2 TCPs surface of section NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Topological entropy NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Interaction of flows NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Interacting traffic flows • Traffic flows crossing the same bottleneck can inherit scaling properties from each other NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Kenesi, Molnár, Veres, Vattay SIGCOMM 2000 NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING
Mode locking structure of adaptation TCP Bandwidth C Background (UDP) Buchta & Vattay 2003 NeXtworking’03 June 23-25,2003, Chania, Crete, Greece The First COST-IST(EU)-NSF(USA) Workshop on EXCHANGES & TRENDS IN NETWORKING