On Fri, Aug 17, 2007 at 05:55:17PM +0100, Michael Rogers wrote: > vive wrote: > > Should be correct directly after generated from Kleinbergs model. But what > > do > > you mean with current locations? Referring here to the current locations on > > the > > circle, where closeness does not have to mean being close in the network > > after > > having swapped and done destination sampling (where positions affect > > swapping). > > Is your suggestion to introduce nodes in roughly the same part of the > > network > > where others just disappeared? > > Not necessarily - wherever the new node appears on the circle, isn't the > important thing the relationship between its distance (on the circle) > from other nodes and its probability of being connected to them?
In the ideal Kleinberg model it is. But when you have randomized positions and swap for positions as in Freenet; then no. Circular distance can no longer be used in the same way by peering with nodes just based on which positions they have taken later on. When you randomize positions you lose the relation between circular distance and distance to "remote parts" of the network. A key point: two nodes separated many steps in the possible shortest route between them may still have ended up with close circular positions. So they are far in the network, but close on the circle. Swapping hopefully gives assigned positions back to a usable level for routing, but not perfectly. Try to see the network from the Kleinberg model as a platonian ideal form. We can try to replicate it by running the swapping algorithm, where nodes will prefer positions based on how they clustered in the original network, but the generated positioning will never (for all practical timescales) be more than a shadow of the perfect network. Hopefully it works rather well (surpringly well in simulation! :)) but still with its small faults and glitches in the assignments which affects the routing. This is also why #freenet-refs between strangers and the darknet model (without opennet) does not give a good result for routing. The ideal topology is not there from the first case. People in the real world seem to form connections so that networks are navigable; #freenet-refs just adds people in a long sequence. The "ideal" topology will not be there from the beginning, not even something that can be used for short routes. Opennet gives something resembling the Kleinberg model, since it adds/rewires connections to other parts of the network, and this is the strong argument for running opennet as long as the network does not grow well enough to resebmle real social clustering. > Why would the connections between the other nodes make a difference? Sorry, I didn't understand that. Kind regards, Vilhelm -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 187 bytes Desc: not available URL: <https://emu.freenetproject.org/pipermail/tech/attachments/20070818/3ee6841a/attachment.pgp>
