[Winpcap-users] WinPCAP packets capture delay..

[Alimjan Kuramshin]

Hello, David!

No, no.. It is just a one of the hundreds test i've done, and i don't measure timestamp spread with it..

Thanks, bye..

22.09.2010, в 13:10, Fish (David B. Trout) написал(а):

> Alimjan Kuramshin wrote:
> 
> (rearranged for clarity)
> 
>> David, can You please see this Wireshark log:
>> http://www.winpcap.org/pipermail/winpcap-
>> users/attachments/20100622/794818cb/attachment-0001.zip
> 
> Yes, I can see what you are talking about.
> 
> 
>> using Winpcap examples, i've write a small test program,
>> when pcap_next_ex return some packet i've send the same
>> (or custom packet) back using pcap_sendpacket
> 
> Whoa! Stop! Why are you doing that?!
> 
> If you are trying to measure the accuracy of WinPCap's timestamp, then you
> should just do the following:
> 
> 1. Send a series of custom packets (using pcap_sendpacket). Each packet
> should have a unique "packet number" in its payload (data). This is so you
> can uniquely identify each packet.
> 
> 2. Use oscilloscope to measure and record the exact delay between each
> packet on the wire.
> 
> 3. Capture those same packets on a completely different computer (i.e. a
> computer that is NOT the one that is sending them).
> 
> 4. Use Wireshark to view the timestamp that the receiving (capturing) system
> assigned to it.
> 
> 5. Verify that the same delay(s) seen physically (via your oscilloscope
> recording) are the same delays on the captured packets as shown by
> Wireshark.
> 
> 
> I'm confused why you are sending what you are receiving? You should be
> sending on one computer and receiving on another. That's it. Nothing more.
> Just send on one computer and capture on another, with the oscilloscope in
> between.
> 
> What you've written above ("when pcap_next_ex return some packet i've send
> the same ... back using pcap_sendpacket") seems to imply you are measuring
> something completely different from what I thought you were measuring.
> 
> -- 
> "Fish" (David B. Trout) 
> fish at softdevlabs.com
> 
> 
> 
> 
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