Ethereal-users: Re: [Ethereal-users] Network Traversal Time

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Date: Wed, 10 Mar 2004 13:48:44 -0600
                                                                           
             Ian Schorr                                                    
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             03/10/2004 12:26          Traversal Time                      
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On Mar 9, 2004, at 3:28 PM, sstudsda@xxxxxxxx wrote:

>>
>> Using NTP to sync the capturing stations to a common time source should
>> provide a consistent time for recording timestamps at each point.  Of
>> course there could be some minor clock drift, but it should be accurate
>> enough that the drift is not going to have a significant impact on the
>> results.
>>
>I don't particularly like this option (or this as the only option)
>because even with the existence of tools like NTP, host clock
>synchronization can be problematic.

The more I've been thinking about this, the more I like the idea of being
able to specify a time difference manually or if not specified assume the
clocks are "synched".

I was also thinking about my comment on performing a bit for bit comparison
or even a hash of the packet for obtaining a signature of the packet.  This
might work for bridged protocols, but would fail miserably with routed
protocols.  The other aspect to this would be the possibility of a device,
like a firewall, rewriting the packet headers and changing IP sequence
numbers and such.  And then there would be packet fragmentation
possibilities to account for.  And I ramble on... =)

>> Hmm, looks like we have found our volunteer.  Now he just needs to
>> dust off
>> his C programming books and start reading some source code.  =)
>
>Ugh.  This requires the volunteer to have spare or dedicated time,  If
>we're waiting on me it will probably be 2005+ before this feature
>appears  =)

Actually, I was volunteering myself in a not so clear manor.  =)
I have some free time to devote to this, but first have to refresh my
programming skills as it has been nearly a decade since I have really used
them (outside of some Perl scripts now and then).

Steve