Content Networking - CON Content Overlay Network

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Content Networking -CON Content Overlay Network

• Vishal Kumar Singh
• Eilon Yardeni
• April, 28th 2005

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Agenda

• Motivation
• Our solution Content Overlay Network
• Overview
• Architecture
• Implementation
• Demo plan
• Future work
• Conclusions

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Motivation

• Problems
• High access latency
• High network load
• High server load
• Web Caches solves this for some extent
• Web Cache serves localized clients
• On Cache miss, Web Cache access the Origin Server

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Content Overlay NetworkOverview

• Distributing Web Caches
• Overlay Network of Web Caches
• Overlay Nodes share cached content
• On Cache miss, nodes access the closest node
  that has the object
• Nodes propagate cache tables
• Nodes perform distance measurement protocol

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• Lookup in local Cache
• Lookup in adjacent nodes Cache
• Fetch from Origin Server
• Serve client

Architecture
Origin Server
Overlay Node
Overlay Node
A
Overlay Node
A
Overlay Node
Overlay Node

• Lookup in local Cache
• Lookup in adjacent nodes Cache
• Fetch from Adjacent node
• Serve client

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Content Overlay NetworkImplementation

• Distance Measurement Protocol
• UDP based RTT measurements
• n2 measurements
• Performed in the background
• Cache table propagation
• Each node periodically propagates its cache table
  diffs to all the other nodes

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Content Overlay NetworkImplementation (Cont.)

• On Cache miss
• Lookup in local cache table
• If found serve the client
• Lookup in adjacent nodes cache tables
• If found and distance is smaller than a
  threshold fetch content from node and serve the
  client
• Update local cache if required
• Access the Origin Server
• Update local cache and serve the client

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Demo plan

• 3 overlay nodes A,B and C
• Browser use A as a proxy
• Cache miss updates As cache
• Browser use B as a proxy
• Cache miss fetch object from A

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Future work

• Measure distance to Origin Servers
• Integrate with open-source Web Cache
• Use DNS measurements
• Overlay bootstrap protocol
• Overtake Akamai

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Open discussion