In the past, people played with routing protocols such as HELLO and FUZZBALL which reacted to the latency on each link. They gave up. It turns out that overly reactive systems are not that useful. The gains are dubious, and the costs on resources are high. The other factor is in what the original poster meant by an "exact" split. Exact over what timeframe? Over any given instant, only one packet is being sent (it's a serial stream) so the split over that amount of time is always 100% of whatever it's doing. On the other hand, if it's an exact split over a fairly long timeslice, you use a class-based queueing system and measure what's been sent out of each queue. You then predict what the net bandwidth is over the whole timeslice, by looking at what gets sent and what gets dropped. Each time you adjust the prediction, you adjust the hard limits for the queues to allow out whatever is left of that class' net bandwidth. A third approach is to see what you can do with ECN and other back-propogating QoS protocols to throttle given queues that reach or exceed their limits. That way, you don't need to care what the bandwidths are at any given time, because the primary router that divvies up the bandwidth can throttle in proportion to how it does that division. --- Rene Gallati <lartc@xxxxxxxxxxxxx> wrote: > Hello, > > > I want to share/split bandwidth on a link with > unknown bandwidth. I > > want to exactly > > share/split bandwidth (for example : FTP 30% , > HTTP 20% or 30% for > > a group of PCs and so forth.) > > > > "Traffic-Control-HOWTO" talk that PRIO scheduler > is an ideal match for > > "Handling a link with a variable (or unknown) > bandwidth". > > > > But PRIO scheduler can not exactly share/split > bandwidth . > > > > Could you tell me if I can exactly share/split > bandwidth on a link with > > a variable (or unknown) bandwidth? If it is > possible, how can I do that ? > > [Warning irony ahead] > I'll give you a complete script if you tell me how > many bits/sec exactly > 30% of unknown is. > [/irony] > > In other words: You don't know how much there is > available, I don't know > it, the list doesn't know it and your computer > can't know it either. > So no - that's not possible (and should be evident, > hopefully) > > What you CAN do is let some ping run alongside and > react to changes in > the latency it sees across the link - then adapt the > script and thus > changing the parameters. This needs lot of > experimentation, is a bad > hack but maybe it is sufficient for what you are > trying to achieve. > > Otherwise, find a minimum value of bandwidth you > never drop below and > set that as the maximum bandwidth available for your > root qdisc. This > gives you the predictability. > > Or : find a better line/ISP. Find and drop abusive > users/applications. > > But all in all, there's not much you can actually do > in your situation. > -- > > C U > > - -- ---- ----- -----/\/ René Gallati > \/\---- ----- --- -- - > > _______________________________________________ > LARTC mailing list / LARTC@xxxxxxxxxxxxxxx > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: > http://lartc.org/ > __________________________________ Do you Yahoo!? Yahoo! Mail - Easier than ever with enhanced search. Learn more. http://info.mail.yahoo.com/mail_250 _______________________________________________ LARTC mailing list / LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
