[LARTC] latency simulation

[LARTC] latency simulation

[Hannes Ebner]

Hi,

how could I achieve a simulation of Bandwidth _and_ Latency?

In detail, I need to simulate the characteristics of ISDN and DSL on a
simple Ethernet-Connection:

    ISDN 64 Kbit/s und 10 ms latency
    DSL 128 Kbit/s und 50 ms latency

I would use HTB for the limitation of the Bandwidth, but how am I able
to increase the latency?

Thank you in advance,
Hannes

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Re: [LARTC] latency simulation

[Stef Coene]

On Tuesday 17 September 2002 16:19, Hannes Ebner wrote:
> Hi,
>
> how could I achieve a simulation of Bandwidth _and_ Latency?
>
> In detail, I need to simulate the characteristics of ISDN and DSL on a
> simple Ethernet-Connection:
>
>     ISDN 64 Kbit/s und 10 ms latency
>     DSL 128 Kbit/s und 50 ms latency
>
> I would use HTB for the limitation of the Bandwidth, but how am I able
> to increase the latency?
Take a look at nist :
http://snad.ncsl.nist.gov/itg/nistnet/
I once tried it and it works.

Stef


-- 

stef.coene@docum.org
 "Using Linux as bandwidth manager"
     http://www.docum.org/
     #lartc @ irc.oftc.net

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Re: [LARTC] latency simulation

[Hannes Ebner]

Hi Leonardo,

 > Have a look to tbf. It has a selectable latency parameter that adjust
 >  the queue length. http://lartc.org/lartc.txt paragraph 9.2.2. Token
 > Bucket Filter can give you more information.

from the HOWTO: "...the latency parameter, which specifies the maximum
amount of time a packet can sit in the TBF...".

_Can_ sit in the TBF, not _will_ sit. Therefore it is also possible to
get the packet forwarded with a latency smaller than the one I have
given to the TBF - but I need a method to decrease it to a fixed amount.

Regards,
Hannes

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Re: [LARTC] latency simulation

[Hannes Ebner]

Hi Stef,

Stef Coene schrieb:
>>I would use HTB for the limitation of the Bandwidth, but how am I able
>>to increase the latency?
> 
> Take a look at nist :
> http://snad.ncsl.nist.gov/itg/nistnet/
> I once tried it and it works.

thank you, a very powerful tool!

Regards,
Hannes

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Re: [LARTC] latency simulation

[Stef Coene]

On Wednesday 18 September 2002 10:06, Hannes Ebner wrote:
> Hi Stef,
>
> Stef Coene schrieb:
> >>I would use HTB for the limitation of the Bandwidth, but how am I able
> >>to increase the latency?
> >
> > Take a look at nist :
> > http://snad.ncsl.nist.gov/itg/nistnet/
> > I once tried it and it works.
>
> thank you, a very powerful tool!
Let me know if it works for you.

Stef

-- 

stef.coene@docum.org
 "Using Linux as bandwidth manager"
     http://www.docum.org/
     #lartc @ irc.oftc.net

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Re: [LARTC] latency simulation

[Leonardo Balliache]

Hi Hannes,

You are right. Thank to Stef for the information. I´ll take a copy too.

Best regards,

Leonardo Balliache

At 06:35 p.m. 18/09/02 +0200, you wrote:
>Message: 5
>Date: Wed, 18 Sep 2002 10:04:36 +0200
>From: Hannes Ebner <he@fli4l.de>
>To: lartc@mailman.ds9a.nl
>Subject: Re: [LARTC] latency simulation
>
>Hi Leonardo,
>
>  > Have a look to tbf. It has a selectable latency parameter that adjust
>  >  the queue length. http://lartc.org/lartc.txt paragraph 9.2.2. Token
>  > Bucket Filter can give you more information.
>
>from the HOWTO: "...the latency parameter, which specifies the maximum
>amount of time a packet can sit in the TBF...".
>
>_Can_ sit in the TBF, not _will_ sit. Therefore it is also possible to
>get the packet forwarded with a latency smaller than the one I have
>given to the TBF - but I need a method to decrease it to a fixed amount.
>
>Regards,
>Hannes



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