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QoS: ADSL OPTIMIZER - подобряване на качеството на ADSL @ the upper layers


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Благодарности на оригиналния автор Jesper Dangaard Brouer, Kernel developer etc.

Моя e-mail до MikroTik support:

<*********@gmail.com> wrote:

> > > No no, My friend, please read the http://www.adsl-optimizer.dk/thesis/main_final_hyper.pdf

What MikroTik dev team could do is thoroughly analyze the ADSL Optimizer and include it as technology in MikroTik RouterOS AS SOON AS PОSSIBLE. Since ADSL is so wide spread!

Quotes from http://www.adsl-optimizer.dk/thesis/main_final_hyper.pdf:

Fig 6.1 Naive overhead approach, queue control is achieved through reducing the rate to 450 Kbit/s. The queue control is lost when the traffic pattern changes.

6.3 Summary

We have demonstrated the effect and magnitude of the ADSL link layer overhead. We show a naive approach for achieving queue control, where the bandwidth is simply reduced a fixed amount to compensate for the overhead. The bandwidth had to be reduced by 62% to handle the worst-case situation. Choosing only to handle an average case packet alignment overhead together with a maximum of 300 packets/s, would require a bandwidth reduction of 33%. The naive approach violates our goal of avoiding to waste link capacity. To achieve queue control, we modify the Linux Traffic Control system to perform accurate link layer overhead modeling. We demonstrate that our implementation is accurate and attains continuous queue control during all traffic patterns.

Furthermore, the solution achieves our goal of avoiding unnecessary waste link capacity when achieving queue control Although, we achieve a satisfying average delay of 44 ms for our high-priority packets, we are not satisfied with the delay variance or delay jitter of 108 ms, as it exceeds the delay jitter requirement of the variation-sensitive service classes.

The following chapter investigates the achievable delay bounds and delay variation for high-priority packets.

> > Hello,

I'm happy to inform you, that setup and behavior described in that thesis is possible with features that we already have in RouterOS:

http://wiki.mikrotik.com/wiki/Packet_Flow

http://wiki.mikrotik.com/wiki/Queue

http://wiki.mikrotik.com/wiki/HTB

http://wiki.mikrotik.com/wiki/PCQ

http://wiki.mikrotik.com/wiki/Burst

http://wiki.mikrotik.com/wiki/Queue_Size

Regards,

Janis Megis

<*********@gmail.com> wrote:

> I am happy to hear this. But how am I going to for example make a queue that compensates for ATM overhead and delay in an optimal way? This is not possible with the current implementation. What MikroTik dev team could do is simply ... make use of the technology to help optimize all customers' adsl links.

Maybe a finished ROS implementation of ADSL optimizer could have an option on a Ethernet interface to set its queue to be ADSL optimized or you could add a default queue type that is ADSL optimized.

Regards.

>

Hello,

Thank you for your recommendations.

Regards,

Normunds

http://www.adsl-optimizer.dk може да се изтегли готов пакет, а това e INSTALL.TXT от него:

~~ $Id: INSTALL.txt 1257 2008-05-12 20:20:21Z brouer $

            ------------------------------------------

              Installation of the ADSL-optimizer

              ------------------------------------------

                Jesper Dangaard Brouer (hawk_AT_diku--dot--dk)

              ------------------------------------------

                    $Date: 2008-05-12 22:20:21 +0200 (Mon, 12 May 2008) $

                          $Revision: 1257 $

              ------------------------------------------

Introduction:

~~~~~~~~~~~~~

The ADSL-optimizer is targeted towards optimizing ADSL lines,

including calculating/accounting for the ATM overhead associated with

ADSL lines.

This file only describes the basic Install recipe.

For configuration see the file: {{design/config.apt}}

Requires:

~~~~~~~~~

The software package have the following requirements. (The module

that the requirement applies to is specified in [] brackets.)

* The "tc" program need at least version 2.6.25 [queues]

* The kernel need to be at least version 2.6.24 [queues]

* The "iptables" software package [filter]

* The "RRDtool" software package including perl RRDs module [graph]

For graph viewing, some RRDtool frontend is needed.  Our graph module

only collects "tc" data into RRDtool files.

We highly recomment "drraw" and supply some example files for "drraw"

(in directory "saved") (which is hardcoded to use files from

\'/var/spool/rrdqueues\').  The example files also uses information

about the physical interface, which is collected with the program

package "rrdcollect" (files stored in \'/var/spool/rrdcollect\').

The latency graph depends on "smokeping", but you will need to adapt

that to your specific setup.

Install instructions step-by-step:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1.)

Unpack the ADSL-optimizer in a directory, preferable:

  "/usr/local/ADSL-optimizer"

(we will refer to this directory as "$BASEDIR")

2.)

Copy the $BASEDIR/sample.conf file to /usr/local/etc/ADSL-optimizer.conf.

(Modify the first line of ADSL-optimizer.conf if not installed in the

  default location "/usr/local/ADSL-optimizer")

3.)

Copy $BASEDIR/filter/expansions.conf.sample to expansions.conf in the

same directory.  Modify "expansions.conf" for your setup, the files

eg. contains the definition of your "LOCALNET" IP-range.

Read the {{design/config.apt}} for modifying the filter setup.

* Init scripts

~~~~~~~~~~~~~~

The init-scripts are located in $BASEDIR/init.d/.

4.) (/etc/init.d/ADSL-filter)

Modify the init-script: "ADSL-filter.init".  It specifies which filter

<base-script> and <scheme-script> to use.

( See under: $BASEDIR/filter/base/ and scheme/ )

Your will need to specify upstream and downstream interfaces

in the ".base" file.

5.) (/etc/init.d/ADSL-queues)

Modify the init-script: "ADSL-queues.init".

It specifies the following parameters:

  * INTERFACE, which is the upstream interface.

  * UPSTREAM, what is the upstream link speed.

  * DOWNSTREAM (optional), only used for ACK rate calc.

  * ACK_RATE (optional), not used if DOWNSTREAM specified.

  * SCRIPT, which queueing script to use.

6.)

Install the init-scripts by hand or use the "install.sh" script in

the $BASEDIR/init.d directory.

* Other

~~~~~~~

7.)

Change the device variabel in the script "tc-collector.pl"

(in $BASEDIR/graph).

Detecting the correct devices is on the TO-DO list...

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Преди време бях теглил подобни неща но малко ме разобедиха че неработили и така и не намерих време да тествам.Ако има вариант за МТ по бих се надъхал.Но и малко не ми е ясно на какъв принцип е основано.освен да филтрира дадени пакети и заявки ама нз :)

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Прочети PDFа, Датчанина е инвестирал 9+ месеца труд и е кърнъл дивелъпър но pdfа е написан достъпно.

Който "не знае" да прочетe PDFа, да узнае, да тества и да поства :)

Мерси.

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Аз нямам adsl, но мога да пробвам да го подкарам на slackware. Така и не свикнах с debian-a, който за тази цел е перфектен. Всякакви обновявания стават с apt-get доста безболезнено за разлика от slack ъпгрейдите :(

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  • 3 weeks later...

Да, изграждането на изходящ HTB решава част от проблема, и ADSL Optimizer-а хвърля светлина върху ATM отместването демек дори и на безшумна ADSL линия - променливия upload, породен от наместването на Ethernet, IP и т.н. върху досадните ATM клетки, които са с малък и фиксиран размер.

Подкарването може да отнеме цял ден :) Ако има ентусиасти - нека да се покажат.

Аз са сега отлагам.

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  • 1 year later...

В момента по-добро решение за оптимизиране на кофти ADSL (и всякакви) линии е това:

http://www.cfos.de/speed/cfosspeed_e.htm

http://www.cfos.de/speed/whatsnew.shtml Добавената функционалност звучи много респектиращо.

Дали си засужава, например в офис, или някъде където се налага да се иползва ADSL, да се добави един Windows hop за оптимизирането?

Бих тествал с удоволствие ::) За сега отлагам. Ако някои има ADSL линия която му се налага да оптимизира, и Windows машина зад нея - да пише (и на ЛС) - ще съдействам за подкарването и тестовете.

Поздрави.

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