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End-to-end QoE Optimization Through Overlay Network Deployment
End-to-end QoE Optimization Through Overlay Network Deployment
Bart De Vleeschauwer, Filip De Turck, Bart Dhoedt and Piet Demeester
Ghent University - Department of Information Technology
Maarten Wijnants and Wim LamotteHasselt University - Expertise Centre for Digital Media
End-to-end QoE Optimization Through Overlay Network Deployment23/01/2008 ICOIN2008 2
Outline
• Introduction & Motivation• Overlay Network Architecture
– Architectural Overview– Overlay server– Overlay access component– Network Intelligence Proxy
• Evaluation– Evaluation Testbed– Experimental Results
• Conclusions
End-to-end QoE Optimization Through Overlay Network Deployment
Introduction & Motivation
• Continuous rise in usage Internet for multimedia services– E.g. IPTV, Skype, online gaming
• Multimedia services are more sensitive to packet loss, bandwidth restrictions, delay and jitter– Network performance guarantees required
• Failure to meet requirements will have impact on user Quality of Experience– E.g. jitter in VoIP = varying response times
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End-to-end QoE Optimization Through Overlay Network Deployment
Introduction & Motivation
• Internet is currently not able to provide any performance guarantees– Routing is best-effort
• Can result in suboptimal routing between hosts• Solutions proposed to provide QoS (e.g. IntServ and
DiffServ) still suffer from unresolved issues
– Last mile can impose bandwidth bottleneck• May result in congestion• Increase in packet loss and packet delay possible
No E2E solution for QoE provision yet available
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End-to-end QoE Optimization Through Overlay Network Deployment
End-to-end Architectural Overview
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Overlaylayer
Networklayer
Last mile QoE optimization
End-to-end QoE Optimization Through Overlay Network Deployment
Overlay Server (OS)
• Monitors connectivity through active network probing– Deduce delay & packet loss on overlay edges
• Maintains a virtual topology using overlay routing tables (ORTs)– ORTs map target OS to next hop OS
• Overlay routing tables are adapted to reflect the current network condition
• Forwards overlay packets via “good” path OSs provide resilient overlay routing
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End-to-end QoE Optimization Through Overlay Network Deployment
Overlay Access Component (AC)
• Deployed at the edge of the network– End-device, residential gateway, …
• Monitors quality of connection (i.e. packet loss & delay) between source-destination
• Packets are pushed to overlay layer in case of problematic direct IP connection– Packets pushed to closest OS– OS forwards packets to AC close to target– AC transfers packets back to IP network layer
Transparent access to overlay network
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End-to-end QoE Optimization Through Overlay Network Deployment
Overlay Routing Example
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End-to-end QoE Optimization Through Overlay Network Deployment
Network Intelligence Proxy (NIProxy)
• Optimizes last mile content delivery to clients– Through awareness introduction in network
• Both network- and application-related context
• Provides client bandwidth management– Through creation stream hierarchy
• Acts as service provision platform– Supports processing of multimedia flows– Through generic plug-in approach– E.g. video transcoding plug-in
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End-to-end QoE Optimization Through Overlay Network Deployment
Evaluation Testbed
• Setup with 10 Linux PCs• Core network and last mile impairment are
emulated using Click nodes
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End-to-end QoE Optimization Through Overlay Network Deployment
Experimental Results – Resilient Overlay Routing
• Packet loss ratio per sec during 50 secs, with and without overlay routing
• 10% average loss• OR: packet loss
circumvented• SR: packet loss,
resulted in visual artifacts at client-side
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End-to-end QoE Optimization Through Overlay Network Deployment
Experimental Results – Last Mile QoE Optimization
• NIProxy managed last mile video delivery• Experiment consisted of 5 intervals
– Caused by both bandwidth fluctuations and client-initiated shifts in stream importance
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Finding 2: more bw for important streamsFinding 1: downstream capacity respectedNo NIProxy: less optimal QoE, e.g. video hitches
End-to-end QoE Optimization Through Overlay Network Deployment
Conclusions
• Overlay network for E2E QoE management– Components in network core and at edge– Improves standard network routing service– Last mile QoE optimization
• Results illustrate effectiveness of approach– Complementarity constituting components– Elimination/decrease packet loss using resilient
overlay routing (e.g. avoiding failing links)– Last mile congestion avoidance through
intelligent bandwidth management and multimedia service provision
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End-to-end QoE Optimization Through Overlay Network Deployment
Thank you for your attention!Any questions?