On Sat, 22 Jan 2011 07:55:34 +1300, Phillip Hutchings wrote: > > On 22/01/2011, at 7:51 AM, Dennis Nezic wrote: > > > On Sat, 22 Jan 2011 07:37:54 +1300, Phillip Hutchings wrote: > >> > >> On 22/01/2011, at 7:34 AM, Dennis Nezic wrote: > >> > >>> On Sat, 22 Jan 2011 07:26:56 +1300, Phillip Hutchings wrote: > >>>> > >>>> On 22/01/2011, at 7:21 AM, Dennis Nezic wrote: > >>>> > >>>>> On Fri, 21 Jan 2011 05:59:06 +0100, David ‘Bombe’ Roden wrote: > >>>>>> a “simple thing” like bandwidth limiting > >>>>> > >>>>> Can someone explain why bandwidth limiting might not be such a > >>>>> simple thing? Volodya tried, with his massive-incoming-packet > >>>>> theory (40KiB :p), but that's not true -- freenet packets are > >>>>> about 1KiB. So, is there not a central class/wrapper in place > >>>>> that feeds the node with at most X KiB / second? Ie. it will > >>>>> only read X UDP packets per second? > >>>> > >>>> It doesn't matter if you only read X packets a second, they've > >>>> still been sent to you so it still used bandwidth. If you don't > >>>> read UDP all that happens is your OS queues for a while the > >>>> starts dropping packets. > >>> > >>> Exactly. Why isn't this being done? > >> > >> Why isn't what being done? There's absolutely no point letting the > >> OS drop the packets. They have already been transmitted, they're > >> in the receiver's memory. Dropping the packets is just wasting > >> time and resources, you have to stop them before they're > >> transmitted. > > > > 1) It puts the user in control. If I specify XKiB/sec, I > > expect/demand XKiB/sec usage :b. > > > > 2) The packets will only be dropped if there is excessive load, > > which obviously should be avoided by all the custom overhead. > > OS-packet dropping would only serve as a last resort -- ie. if > > freenet's traffic-coordination messes up (as it currently > > does! :p), or if we are connected to malicious nodes. > > > > There are two options here -- either we respect the sender's wishes > > (and thus optimize efficiency/network performance), or we respect > > the user's/receiver's wishes, and potentially lose a little > > efficiency/performance. (Guess which option is the right option :b) > > I don't understand what you're getting at. So if you say you want > XKiB/sec you want freenet to read XKiB/sec, regardless of what it's > actually using?
Precisely. > The important point is: > - Once the packet is in the receiver's queue it has _already_ been > received. If the limiter has messed up it's too late to fix it. > > It's like deciding to dump half your fuel tank after paying because > you only wanted to fill half way. Precisely. (There is no real limiter, in the scenario you're proposing though. At some point, packets will need to be dropped. How would you distinguish between a DDOS attack, and enthusiastic super-nodes?) (I'm actually not quite sure how the traffic flows -- are packets pushed onto other nodes, or are they pulled?) _______________________________________________ Support mailing list Support@freenetproject.org http://news.gmane.org/gmane.network.freenet.support Unsubscribe at http://emu.freenetproject.org/cgi-bin/mailman/listinfo/support Or mailto:support-requ...@freenetproject.org?subject=unsubscribe
