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

• ?? || //