Thank you very much, i will try to find these papers which must be very helpful for me. The "more" means that whether there are other mechanisms not only for Linux. Sorry, i have not make it clear! Sometimes, i wonder whether the qdiscs such as CBQ, RED, GRED ... are belong to the scheduler mechanisms in linux enviroment. For example, In Red, which i can find are enqueue, and dequeue.... so, if i add a RED qidsc to a class, must i add a scheduler mechanism so that i can decide which packet in the queues will be scheduled and put to the link? Good luck, Best, >It depends on what you mean by "more". More for Linux? > Certainly. HTB3 seems to be a popular mechanism, and > you can use IMQ to set up an intermediate device to > allow shaping of both inbound and outbound traffic, > using one (or more!) scheduling mechanisms in series. > > (In fact, there are several versions of IMQ out there. > I've given links to both the projects that seem to be > alive, but there may be more.) > > There's also ESFQ, but there doesn't seem to be much > active work on that. There are forward ports to recent > Linux kernels, though. QLinux has a version of H-SFQ > for Linux, but again it seems to be getting long in > the tooth. Unfortunately, I can't find any forward > ports of that. > > http://luxik.cdi.cz/~devik/qos/htb/ > http://www.linuximq.net/ > http://pupa.da.ru/imq/ > > http://www.digriz.org.uk/jdg-qos-script/#qos-2.6 > http://kem.p.lodz.pl/~peter/qnet/ > http://lass.cs.umass.edu/software/qlinux/ > > There are a great many systems that I can't find a > Linux version of. Cisco routers support something > called "Class-Based Weighted Fair Queueing" (CBWFQ) > which seems to be a hybrid of classful and classless > scheduling. Cisco also has two versions of ECN, for > forwards and backwards propogation. > > I've listed below a number of papers detailing various > QoS schemes. Some of these have been implemented in > other OS' (the BSDs tend to get a lot of this stuff > implemented quickly for them as part of ALTQ) and some > I've never seen an implementation at all. However, the > papers should all give enough information to write a > version for Linux. > > Note: ALTQ can be found at: > http://www.csl.sony.co.jp/person/kjc/kjc/software.html > > Please note that this list is not exhaustive. Rather, > I got exhausted after trying to find what was out > there and what state it was currently in. QoS is a big > field, if the number of papers is anything to go by. > Linux only touches the fringes of it. If anyone feels > particularly bored, or in need of a good ego boost, it > would be cool to see if a reasonable selection of > these could be introduced into Linux over the 2.7 > cycle. > > EDF (Earliest Deadline First) > http://citeseer.ist.psu.edu/13919.html > > BLUE (an alternative to RED) > http://citeseer.ist.psu.edu/feng99blue.html > > AF PHB (Assured Forwarding Per-Hop Behaviour) > http://citeseer.ist.psu.edu/552302.html > > SFB (Stochastic Fair Blue) > http://citeseer.ist.psu.edu/551253.html > > GREEN (a pro-active variant on the theme of RED) > http://citeseer.ist.psu.edu/feng02green.html > > SMART (Scalable Multipath Aggregated RouTing) > http://citeseer.ist.psu.edu/vutukury00smart.html > > CSFQ (Core Stateless Fair Queueing) > http://citeseer.ist.psu.edu/391.html > > StFQ (Start-Time Fair Queueing) > http://citeseer.ist.psu.edu/goyal96starttime.html > > RFQ (Rainbow Fair Queueing) > http://citeseer.ist.psu.edu/cao00rainbow.html > > PrFQ (Probabalistic Fair Queueing) > http://citeseer.ist.psu.edu/anker00prfq.html > > ERR (Elastic Round Robin) > http://citeseer.ist.psu.edu/kanhere02fair.html > > GFQ (Greedy Fair Queueing) > http://citeseer.ist.psu.edu/690207.html > > PERR (Prioritized Elastic Round Robin) > http://citeseer.ist.psu.edu/681127.html > > AOQ (Anchored Opportunity Queueing) > http://citeseer.ist.psu.edu/701742.html > > BSFQ (Bin Sort Fair Queueing) > http://citeseer.ist.psu.edu/622188.html > > > As for the final question on what happens between > enqueue and dequeue, there are various diagrams out > there which show different aspects of how packets > traverse the system. I've included a few links to > those I could find: > > http://open-source.arkoon.net/kernel/kernel_net.png > http://ebtables.sourceforge.net/br_fw_ia/PacketFlow.png > http://ebtables.sourceforge.net/br_fw_ia/br_fw_ia.html > http://www.docum.org/docum.org/kptd/ > > The last of these is the infamous Kernel Packet > Travelling Diagram. Most links to this that I've been > able to find are broken. It should be noted that the > diagrams all refer to the Linux 2.4 kernel. Linux 2.6 > has quite a few QoS changes to it, but I'm unclear as > to whether they significantly alter any of the flows. > > I hope this is of some use. Or, at the very least, is > an effective remedy to insomnia. :) > > Jonathan > > --- Zhenyu Wu <y030729@xxxxxxxxxxxx> wrote: > > > Hello, > > > > Normally, in addition to such qdisc scheduler > > mechanisms as FIFO, PQ, WRR, WFQ, > > are there any more? Then, there is a confusion on > > scheduler in Linux enviroment: > > Assume there is a qdisc, such as RED as a leaf qdisc > > in a router, we know, if > > there is packet which want to enqueue the packet, > > the Function red_enqueue is > > called, but when the packet leave the queue(when the > > Function red_dequeue is > > called)? I think it is meaningless when the pack > > leaves the queue just it enterred > > it. Is there anything need to be done betweent the > > packet's enqueue and dequeue? > > > > Best, > > > > > > _______________________________________________ > > LARTC mailing list / LARTC@xxxxxxxxxxxxxxx > > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: > > http://lartc.org/ > > > > > > > __________________________________ > Do you Yahoo!? > Jazz up your holiday email with celebrity designs. Learn more. > http://celebrity.mail.yahoo.com > > _______________________________________________ LARTC mailing list / LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
