Network Layer Support for Overlay Network

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Network Layer Support for Overlay Network

• John Jannotti
• MIT EECS
• Ph.D Thesis

MIT LCS Parallel and Distributed Operating
Systems Group
Aug. 2002
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Author

• Postdoctoral Scholar
• Publish
• John Jannotti, David K. Gifford, Kirk L. Johnson,
  M. Frans Kaashoek, James O'Toole Jr. Overcast
  Reliable Multicasting with an Overlay Network.
  OSDI 2000
• Eddie Kohler, Robert Morris, Benjie Chen, John
  Jannotti, M. Frans Kaashoek The click modular
  router. TOCS 2000
• Jinyang Li, John Jannotti, Douglas S. J. De
  Couto, David R. Karger, Robert Morris A scalable
  location service for geographic ad hoc routing.
  MOBICOM 2000

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Outline

• Problem
• Packet Reflection
• Path Painting

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Problem

• Stress The number of times that a semantically
  identical packet traverses a given link
• Stretch The ratio of latency in an overlay
  network.

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Problem
E2 receives packets only after they have
traversed eight links, rather than the four of a
direct unicast
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Packet Reflection
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Packet Reflection (cont.)
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Packet Reflection (cont.)
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Packet Reflection (cont.)

• Handshake mechanism
• ASK
• Offer
• Demand

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Packet Reflection (cont.)
Fig. 1

• ASK
• Initiate the request.
• It contains a list of copies that the requester
  would like made on its behalf

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Packet Reflection (cont.)
Fig. 2

• OFFER
• OFFER lists the subset of copies from the ASK
  that the router is willing to service
• Nonce
• Cryptographically generated integer

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Packet Reflection (cont.)
Fig. 3

• DEMAND
• A DEMAND contains the nonce of the OFFER.
• It will also contain the same copy info as the
  OFFER.

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Packet Reflection (cont.)
ASK
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Packet Reflection (cont.)
Offer Nonce
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Packet Reflection (cont.)
Demand Nonce