[LARTC] measuring performance time in a node using ethereal/tcpdump

[LARTC] measuring performance time in a node using ethereal/tcpdump

[nitin panjwani]

Hi All, 

We are doing some experiment, where we are trying to
measure the processing time taken by a node when a
packate pssess throgh it. 

        --------eth0[Linux-PC Router]eth1------- 

We run tethereal within this PC at eth0(incomming
interface) and eth1(outgoing interface) . Then we find
out our packate in  both the captures and the
difference of two captures gives processing time of
the node 

Now, the question: Is doing so a right way to measure
the processing time, as we are not sure where exactly
does libcap captures the packates. Is it right before
network driver or after it ao anywhere else? 

I just came to know that On Linux, libpcap captures
packets using PF_PACKET sockets (or, on 2.0
kernels or with libpcap built on a 2.0-kernel system,
PF_INET/SOCK_PACKET sockets).

Any help on this issue will be highly appreciable. 

Thanks, 

Nitin 

 





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Re: [LARTC] measuring performance time in a node using ethereal/tcpdump

[Stef Coene]

On Friday 29 November 2002 01:21, nitin panjwani wrote:
> Hi All,
>
> We are doing some experiment, where we are trying to
> measure the processing time taken by a node when a
> packate pssess throgh it.
>
>         --------eth0[Linux-PC Router]eth1-------
>
> We run tethereal within this PC at eth0(incomming
> interface) and eth1(outgoing interface) . Then we find
> out our packate in  both the captures and the
> difference of two captures gives processing time of
> the node
>
> Now, the question: Is doing so a right way to measure
> the processing time, as we are not sure where exactly
> does libcap captures the packates. Is it right before
> network driver or after it ao anywhere else?
>
> I just came to know that On Linux, libpcap captures
> packets using PF_PACKET sockets (or, on 2.0
> kernels or with libpcap built on a 2.0-kernel system,
> PF_INET/SOCK_PACKET sockets).
>
> Any help on this issue will be highly appreciable.
Why not using 2 extra boxes.  If you send a packet from left to right and the 
right hosts responds immediate (ping or so), so the packet returns, you know 
the processing time. 
I think there are also traffic generator tools that can monitor delays and 
jitter.

Stef

-- 

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

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Re: [LARTC] measuring performance time in a node using ethereal/tcpdump

[Martin A. Brown]

The mailing list that refers to itself:

  http://mailman.ds9a.nl/pipermail/lartc/2001q1/000671.html

 : I think there are also traffic generator tools that can monitor delays and 
 : jitter.

-Martin

-- 
Martin A. Brown --- SecurePipe, Inc. --- mabrown@securepipe.com



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