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Simulation Model for End-to-end QoS across Heterogeneous Networks. C. Cicconetti and G. Stea , University of Pisa, Italy G. Garcia de Blas, Telefónica I+D, Spain X. Masip, Technical University of Catalunya, Spain J. Sá Silva, University of Coimbra, Portugal
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Simulation Model for End-to-end QoS across Heterogeneous Networks C. Cicconetti and G. Stea, University of Pisa, Italy G. Garcia de Blas, Telefónica I+D, Spain X. Masip, Technical University of Catalunya, Spain J. Sá Silva, University of Coimbra, Portugal G. Santoro, University of Rome "La Sapienza", Italy H. Tarasiuk, Warsaw University of Technology, Poland
Outline • This presentation is about • Simulation in the EuQoS project • Overview of the EuQoS packet-level simulator • Description of the access and core networks • Description of the traffic models • Preliminary performance evaluation
Simulation models • Simulation is for validatingand assessing the performance ofthe EuQoS system • Two simulators for the EuQoS project • Flow Level simulator • Flow setup/teardown are the events driving simulation • Assess (e.g.) resource reservation and admission control • Packet level simulator • Packets are transmitted • Assess packet-wise measures, e.g. e2e delay and jitter • This work describes the packet-level simulator
Overview of the Packet Level Simulator Access networks connected to the core through a single link No. of flows is fixed Routing does not change Traffic distinguished into Foreground, i.e. applications which are actually measured Background, i.e. aggregated interference traffic Hypotheses
Access networks • Four different access networks are considered: WiFi UMTS xDSL Ethernet
Access Networks: UMTS Urban and rural scenarios considered Different propagation and mobility models Single Node B Intercell interference accounted for by using interference models DSCH and DCH implemented
Access Networks: WiFi Nodes using DCF in an 802.11 infrastructure mode network (802.11e left for the 2nd phase) RTS/CTS handshake Fragmentation No mobility simulated Channel error models to be added No power saving nor rate switching
Access Networks: Ethernet • Switched Ethernet: • Small Office Home Office (SOHO) • Campus/LAN scenario • MAN organization scenario • MAN residential scenario (EPON) • 802.1p and 802.1q standards implemented
Core Network DiffServ-capable routers with (at least) 2 PHBs QoS-oriented classification, policing and scheduling mechanisms enforced Interfering traffic represents aggregated traffic from access networks and core domains Bottlenecks are at the inter-domain links
Traffic models Foreground traffic VoIP G.711, G.729 codecs with VAD Video Conference MPEG4 and H263 VC traces Video streaming MPEG 4 encoded movies Input expected from application developers in EuQoS Background traffic Depends on the network (access tech. and core) Depends on what applications are actually used Many models available in the literature Input expected from measurement activities in EuQoS
Implementation of the packet level simulator • Ns-2 has been used • Devised a framework that allows the seamless addition of new modules • Simulation scenarios can be built incrementally
A simple heterogeneous simulation scenario • First simulations showing the need for e2e QoS
Conclusions and future work • Conclusions • We have designed and developed a flexible simulation system, aimed at verifying e2e QoS on a path of heterogeneous networks • Still much to be done… • Assess the performance of the solutions that are being (and will be) proposed within the EuQoS project • Provide insight on the QoS interoperability across heterogeneous networks • Support the development of new algorithms and mechanisms
Acknowledgements • Thanks to all the people involved in the simulation activities within WP2: • L. Lenzini, E. Mingozzi, University of Pisa, Italy • M. L. García Osma, Telefónica I+D, Spain • S. Sánchez, J. Domingo-Pascual, UPC, Spain • M. Carmo, University of Coimbra, Portugal • A. Angelini, M. Cavicchioni, V. D’Eri, D. Fiorentini, R. Proietti, University of Rome "La Sapienza", Italy • R. Janowski, J. Sliwinski, W. Burakowski, D. Duda , WUT, Poland
End of presentation • Thanks for listening • ?? || //