Simulation Model for End-to-end QoS across Heterogeneous Networks
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Transcript of Simulation Model for End-to-end QoS across Heterogeneous Networks
Slide 1© EuQoS consortiumIPS MoMe, Warsaw, March 2005
Simulation Model for End-to-end QoS across Heterogeneous
Networks
C. Cicconetti and G. Stea, University of Pisa, ItalyG. Garcia de Blas, Telefónica I+D, SpainX. Masip, Technical University of Catalunya, SpainJ. Sá Silva, University of Coimbra, PortugalG. Santoro, University of Rome "La Sapienza", ItalyH. Tarasiuk, Warsaw University of Technology, Poland
Slide 2© EuQoS consortiumIPS MoMe, Warsaw, March 2005
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
Slide 3© EuQoS consortiumIPS MoMe, Warsaw, March 2005
Simulation models
• Simulation is for validating and assessing the performance of the 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
Slide 4© EuQoS consortiumIPS MoMe, Warsaw, March 2005
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
Access Network 1
Core Network
Access Network 2
Hypotheses
Slide 5© EuQoS consortiumIPS MoMe, Warsaw, March 2005
Access networks
• Four different access networks are considered:
UMTS
xDSL
Core network
WiFi
Ethernet
Slide 6© EuQoS consortiumIPS MoMe, Warsaw, March 2005
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
UE
UE
UE
UE
Node B
RNC
Node B
UTRAN
SGSNGGSN
UMTS CN
To EuQoS Core
Network
Slide 7© EuQoS consortiumIPS MoMe, Warsaw, March 2005
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
Core network
Access Point
Wireless stations
Slide 8© EuQoS consortiumIPS MoMe, Warsaw, March 2005
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
Slide 9© EuQoS consortiumIPS MoMe, Warsaw, March 2005
Access Networks: xDSL
Slide 10© EuQoS consortiumIPS MoMe, Warsaw, March 2005
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 Sink Traffic Sink Traffic Sink
Edge or Border RouterBottleneck A
Edge or Border RouterBottleneck A
Core Router Intra-domain Link
Inter-domain Link
Inter-domain Link
Interfering Traffic Generator 2
Interfering Traffic Generator 1
Interfering Traffic Generator 2
QoS domain
Core network
QoS Domain
Slide 11© EuQoS consortiumIPS MoMe, Warsaw, March 2005
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
CoreAccess
Network 1Access
Network 2
BgndTraffic
BgndTraffic
BgndTraffic
Foreground traffic
Slide 12© EuQoS consortiumIPS MoMe, Warsaw, March 2005
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
Main Module
Technology-independent Modules
Technology-dependent Modules
Traffic
Measurement
xDSL LAN
IP Core Network
Grid
WiFi UMTS
Slide 13© EuQoS consortiumIPS MoMe, Warsaw, March 2005
Core network802.1p Ethernet
bi-directionalVoIP + videoconference
802.11g AP
A simple heterogeneous simulation scenario
• First simulations showing the need for e2e QoS
Traffic type Ethernet Core WiFi
Hi-pri PremiumSame
treatmentLo-pri Best Effort
Slide 14© EuQoS consortiumIPS MoMe, Warsaw, March 2005
Evaluation of delay and jitter
Add background traffic at…
Ethernet Core WiFi
t=20s t=40s t=60s
Slide 15© EuQoS consortiumIPS MoMe, Warsaw, March 2005
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
Slide 16© EuQoS consortiumIPS MoMe, Warsaw, March 2005
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
Slide 17© EuQoS consortiumIPS MoMe, Warsaw, March 2005
End of presentation
• Thanks for listening
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