DNSR: Domain Name Suffix-based Routing in Overlay Networks

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DNSR Domain Name Suffix-based Routing in Overlay
Networks
Dept. of Computer Science Engineering. Universit
y of California - Riverside
CS202 Advanced O.S Spring 03

• Demetrios Zeinalipour-Yazti

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Introduction

• Most overlay networks dont match the underlying
  topology
• Transcontinental connections are expensive.
• It would be desirable to keep the bulk of the P2P
  traffic within the same domain

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Motivation

• Analyzing the Gnutella Network
• D. Zeinalipour T. Folias, cs204 Course
  Project
• We analyzed 300,000 IP addresses.
• 58.73 of Gnutella IPs belongs to only 20 ISPs.
• Organizing Peers into domains rather than loosely
  interconnecting them might be feasible

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DNSR Idea

• DNSRDomain-Name Suffix-based Routing
• Decentralized Routing Algorithm that attempts to
  keep P2P traffic within the same domain.
• DNSR defines three Level factors per peer
• Sibling Factor (sfi)
• Parent Factor (pfi)
• Children Factor (cfi)
• DNSR also defines a similarity function
  -suffix

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DNSR Topology

• Given that each node maintains the Level Factors
  we end up with a semi-hierarchical topology.

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Joining a DNSR Topology

• A node obtains a random list from an out-of-band
  mechanism (e.g. hostcache).
• It probes for best entry point with Lookup

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Searching a DNSR Topology

• Searching can be done with a variety of
  techniques (BFS, Random BFS,.)
• The bottom-line with all techniques is that the
  bulk of the traffic remains within the same
  domain

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Experimental Setup

• Scenario
• We generate a DNSR topology and a Random Topology
  of 1000 nodes with following distributions
• We deploy the 1000 real nodes on 25 machines
• We run a number of queries and observe the
  distribution of hosts contacted in each case.

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Experimental Evaluation

• Each node reads its settings from the filesystem
• All nodes are launched concurrently with ssh
  public/private keys making the bootstrapping easy.

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Experimental Results
Level 0

• We connect to a .rr.com host
• Submit 40 queries and count the number of hosts
  contacted C.
• In a random topology C matches the actual
  distribution of hosts
• In a DNSR topology most of the hosts contacted
  are .com hosts for level 0.

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Experimental Results
Level 1

• For Level 1 we can see that in DNSR topology we
  will contact more .rr.com hosts than with a
  random topology.
• Therefore more traffic remains within same domain
• Sibling Factor was 66. If it was larger then 24
  would be larger

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DNSR Demo Follows
Dept. of Computer Science Engineering. Universit
y of California - Riverside