* Re: [LARTC] external and internal LANs
2005-05-25 10:52 [LARTC] external and internal LANs rani79
@ 2005-05-25 23:55 ` Jody Shumaker
2005-05-26 11:57 ` rani79
1 sibling, 0 replies; 3+ messages in thread
From: Jody Shumaker @ 2005-05-25 23:55 UTC (permalink / raw)
To: lartc
What basically happens is that the slowest link ends up controlling the
shaping. Usually this is the device connecting you to your ISP, and it
tends to have a very simple buffering of data, FIFO, first in first
out. What this ends up meaning is that when you send data to it at the
much faster rate of your local network, eventually you fill the buffer,
at that point it just starts dropping packets. It's actually much more
complicated than this, but all you need to know is that he buffer before
the slowest link can only hold so many, and how it sends out what its
holding is the important thing. With a simple fifo queue you may have a
bunch of data from an ftp transfer sitting in the queue, then you add a
http request to the end of the queue. The http request has to wait till
all that ftp data gets sent, even though it's a really tiny bit of data.
If you instead shape the data on the linux router, you can make yourself
the slowest link. By doing so you prevent the simple queue from filling
up much, and can implement some sort of priorities for traffic. If you
gave http request more priority than ftp data, then even if your queue
is full of ftp data, when the http request comes along it will get sent
as soon as possible instead of waiting for all the ftp packets already
on the queue to be sent out.
Giving TCP Ack packets higher priority is another common practice. Even
when you're just downloading data, from say a website or ftp, ackowledge
packets are sent to ackowledge you got each piece of data. The other
end will only send so much data before it waits to receive ack packets.
Giving these rather small packets priority, your downloads will never
suffer because of your uploads.
rani79@idm.net.lb wrote:
>hi all
>what does it mean if the total network speed on internal LAN is greater
>than the external LAN
>and why it happens?
>the extrnal LAN here is the Intenet using a dedicated bandwidth. and
>BTW the linux box NATting
>has no shapping at all. just direct piping
>
>_______________________________________________
>LARTC mailing list
>LARTC@mailman.ds9a.nl
>http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
>
>
>
_______________________________________________
LARTC mailing list
LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [LARTC] external and internal LANs
2005-05-25 10:52 [LARTC] external and internal LANs rani79
2005-05-25 23:55 ` Jody Shumaker
@ 2005-05-26 11:57 ` rani79
1 sibling, 0 replies; 3+ messages in thread
From: rani79 @ 2005-05-26 11:57 UTC (permalink / raw)
To: lartc
i donno u seem right but i am not yet convinced.
what i have here actually is that before i install the linux router there was
a windows server with its caching server ISA. when i retun the windows
server (ISA) back the speed returns to very high dedicated speed i
bought from my ISP. what have really is 51 kbyte/sec. but i use linux i get
only 16 kbyte/sec.
the connection is as follows:
1- wireless connection from satallite thru penta card for down link only
2- then the ISA after the penta. which is a NAT server for 4 networks.
3- a cisco router for the UP link
so rather i take 51, i take 16 and what i have done is just replacing a
mechine and pass the internet thru my linux, which has squid as
trasnparent cache, WITHOUT ANY USE OF `tc` COMMAND OR ANY
KIND OF SHAPING!!!
THANKS.
----- Original Message -----
From: Jody Shumaker <jody.shumaker@gmail.com>
Date: Thursday, May 26, 2005 2:55 am
Subject: Re: [LARTC] external and internal LANs
> What basically happens is that the slowest link ends up
> controlling the
> shaping. Usually this is the device connecting you to your ISP,
> and it
> tends to have a very simple buffering of data, FIFO, first in
> first
> out. What this ends up meaning is that when you send data to it
> at the
> much faster rate of your local network, eventually you fill the
> buffer,
> at that point it just starts dropping packets. It's actually much
> more
> complicated than this, but all you need to know is that he buffer
> before
> the slowest link can only hold so many, and how it sends out what
> its
> holding is the important thing. With a simple fifo queue you may
> have a
> bunch of data from an ftp transfer sitting in the queue, then you
> add a
> http request to the end of the queue. The http request has to
> wait till
> all that ftp data gets sent, even though it's a really tiny bit of
> data.
> If you instead shape the data on the linux router, you can make
> yourself
> the slowest link. By doing so you prevent the simple queue from
> filling
> up much, and can implement some sort of priorities for traffic.
> If you
> gave http request more priority than ftp data, then even if your
> queue
> is full of ftp data, when the http request comes along it will get
> sent
> as soon as possible instead of waiting for all the ftp packets
> already
> on the queue to be sent out.
>
> Giving TCP Ack packets higher priority is another common practice.
> Even
> when you're just downloading data, from say a website or ftp,
> ackowledge
> packets are sent to ackowledge you got each piece of data. The
> other
> end will only send so much data before it waits to receive ack
> packets.
> Giving these rather small packets priority, your downloads will
> never
> suffer because of your uploads.
>
>
>
> rani79@idm.net.lb wrote:
>
> >hi all
> >what does it mean if the total network speed on internal LAN is
> greater
> >than the external LAN
> >and why it happens?
> >the extrnal LAN here is the Intenet using a dedicated bandwidth.
> and
> >BTW the linux box NATting
> >has no shapping at all. just direct piping
> >
> >_______________________________________________
> >LARTC mailing list
> >LARTC@mailman.ds9a.nl
> >http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
> >
> >
> >
>
> _______________________________________________
> LARTC mailing list
> LARTC@mailman.ds9a.nl
> http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
>
_______________________________________________
LARTC mailing list
LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
^ permalink raw reply [flat|nested] 3+ messages in thread