1. A Scalable content-addressable network
Presenter: Baoning Wu

2. Motivation
Many peer-to-peer systems appear, but most of them are not scalable.
Napster needs a central server to store index of all files.
Gnutella floods request with a certain scope.
Can we have a scalable p2p file distribution system?

3. CAN (content-addressable network)
Scalable indexing mechanism is crucial in scalable p2p systems.
Hash table is used!
(key, value) pair
Each CAN node stores a chunk(zone) of the entire hash table

4. Design D-dimensional Cartesian co-ordinate space
Map key to a point P with a determined hash function
Routing the request if the point P is not owned by the requesting node or its immediate neighbors.

5. Picture

6. Routing detail
Each CAN node maintains coordinate routing table that holds the IP address and virtual coordinate zone of its neighbors.
Routing a message towards its destination by simple greedy forwarding to the neighbor with coordinated closest to the destination coordinates.

7. Design improvement: Multi-dimensioned coordinate spaces

8. Design improvement: Multiple coordinate spaces

9. Design improvement: multiple dimensions vs. multiple realities

10. Design improvement: RTT weighted routing

11. Design improvement: multiple nodes share a zone

12. Design improvement: multiple hash functions

13. Design improvement: topologically-sensitive construction

14. Review Dimensionality Number of realities
Number of peer nodes per zone
Number of hash functions
Use of RTT weighted routing metric
Use of topologically-sensitive construction

15. QUESTIONS?