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Getting higher in the SpoVNet stack Services in SpoVNet Reside - PDF document

Considering Network Heterogeneity in Global Application Layer Multicast Provision Christian Hbsch Institute of Telematics, University of Karlsruhe (TH) 8th Wrzburg Workshop on IP: Joint EuroNF, ITC, and ITG Workshop on Visions of Future


  1. Considering Network Heterogeneity in Global Application Layer Multicast Provision Christian Hübsch Institute of Telematics, University of Karlsruhe (TH) 8th Würzburg Workshop on IP: Joint EuroNF, ITC, and ITG Workshop on “Visions of Future Generation Networks” (EuroView2008) July 21st - July 22nd 2008, Würzburg/Germany Getting higher in the SpoVNet stack… Services in SpoVNet Reside above Application Application Underlay Abstraction Service abstraction Offer interface to applications Services Several services as part of the Cross-layer information Underlay abstraction architecture SpoVNet Base MCP-O (Data Dissemination) Security ES (Event Service) Base Overlay Security Service Base Communication Focus here: MCP-O Underlay 1 EuroView2008 - Christian Hübsch Considering Network Heterogeneity in Global ALM Provision

  2. Goal: Efficient Data Dissemination Group Communication in SpoVNet instances Router End System Solution: Application Layer Multicast (ALM) Overlay Link Underlay Link Several existing approaches Narada, NICE, Yoid, Nemo, … Each with different target applications Drawbacks Considering homogeneous (UDP-)underlays Measure link property themselves • Mostly latency SpoVNet Vision Global service provision • Heterogeneity of nodes and network! Different application demands 2 EuroView2008 - Christian Hübsch Considering Network Heterogeneity in Global ALM Provision NICE Achieve scalability through hierarchical clustering Limit protocol overhead Consider node distances (n-2-n latencies) Logical structure determines date dissemination Cluster Leader Cluster Member Cluster 3 EuroView2008 - Christian Hübsch Considering Network Heterogeneity in Global ALM Provision

  3. MCP-O Protocol Design Basic idea (enhance NICE approach to…) Evaluate application demands for structural design decisions Consider Cross-Layer-Information (provided by CLIO comp.) Built efficient dissemination topologies for every use case Use underlay functionality where possible Structure Application QoS Info Request (QoS) Requirements N-2-n-Links Base CLIO MCP-O Link QoS Info Request 4 EuroView2008 - Christian Hübsch Considering Network Heterogeneity in Global ALM Provision Service Demands Adaption Use Service Metric to affect building of structure Weights a i determined through application requirements f i (x,y) e.g. latency, same WiFi domain, same IP Multicast domain, … Cluster Leader Cluster Member Cluster IP Multicast Broadcast Domain Domain 5 EuroView2008 - Christian Hübsch Considering Network Heterogeneity in Global ALM Provision

  4. Service Demands Adaption But: Hierarchical approach not always the best choice Good scalability, but cutting back e.g. latencies � Example: Latency-sensitive app with < 16 Members Adapt cluster size K K = (lowest current upstream) / (data stream) Unicast brings best achievable latency, protocol decides reasonable overhead in bounds 6 EuroView2008 - Christian Hübsch Considering Network Heterogeneity in Global ALM Provision Examples for Protocol Behavior Single Source Videostreaming application Locate High-Bandwidth nodes near source Make them cluster leader, upstream determines cluster size � Flat tree to bound latency and jitter Realtime Game Latency critical factor Use unicast where feasible 7 EuroView2008 - Christian Hübsch Considering Network Heterogeneity in Global ALM Provision

  5. WiFi Integration First Steps: Wireless Integration Save transmission overhead through broadcast � NICE-WLI Introduce Gateway-Nodes for mediation WiFi domain not part of structure, but connected through Gateway Prevent Gateways from becoming cluster leaders (save overhead) AP 8 EuroView2008 - Christian Hübsch Considering Network Heterogeneity in Global ALM Provision WiFi Integration Approach saves data transmission overhead Figure: P(WLAN) denotes probability of WiFi node Traffic per node Node count 9 EuroView2008 - Christian Hübsch Considering Network Heterogeneity in Global ALM Provision

  6. Summary & Outlook Efficient data transmission for SpoVNet applications through Considering node and network heterogeneity Use appropriate dissemination strategies • IP Multicast, broadcast, QoS reservations,… WiFi support already integrated Further Work Multiple group support per instance Usage of underlay features 10 EuroView2008 - Christian Hübsch Considering Network Heterogeneity in Global ALM Provision

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