On Wed, Apr 12, 2006 at 06:59:59PM +0100, Michael Rogers wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > >>* Despite being well designed and widely tested, TCP is not suitable for > >>end-to-end congestion control in Freenet > > > > > > Then what is? > > I'm not sure congestion control should be done end-to-end in Freenet. > Instead, each node's traffic should be limited by its immediate > neighbours, and each node should route around its overloaded neighbours.
I don't think this is viable. It is necessary to propagate load back to its originators. Otherwise everyone is overloaded and all the traffic is routed to the least overloaded nodes. > > > I don't see that you are actually addressing the problem here. How do we > > limit the amount of load the node can place on the network? > > Let's say we have perfect fair queueing. If a selfish node's neighbours > are honest then they'll only give it a fair share of their bandwidth. On > the other hand if they're selfish too then they'll give it nothing - > either way it gets less than if they just forwarded packets on a > first-come first-served basis. > > > Yes we > > should have fair queueing, but we need to have the requestors slow down > > according to network load in order to minimize backoff. > > Fair queueing achieves this to some extent because if your packets are > in a separate queue from everyone else's and you start to experience > packet loss, the only way to prevent further loss is to reduce your own > transmission rate - you can't force anyone else to back down. Well we need an algorithm for this! > > However this assumes the closest link is the bottleneck - I'm not sure > whether the same would be true if you could be sure that the bottleneck > was more than one hop away, where your packets would be sharing a queue > with other nodes' packets... > > >> * No incentive to forward inserts (but is this even possible, > >>since there's no way to verify they've been forwarded?) > > > > > > Well there is if they succeeded. > > Is it possible to distinguish a genuine "insert succeeded" from a fake one? Not easily. > > Cheers, > Michael -- Matthew J Toseland - toad at amphibian.dyndns.org Freenet Project Official Codemonkey - http://freenetproject.org/ ICTHUS - Nothing is impossible. Our Boss says so. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: Digital signature URL: <https://emu.freenetproject.org/pipermail/devl/attachments/20060412/cb777751/attachment.pgp>
