[Winpcap-users] Packets capture latency

[Alimjan Kuramshin]

:(

Well, i don't know what todo.
I've used timeout value within 0 or -1, no luck. Mintocopy, different values, from 8 to 1024, no luck.
CPU usage reaches ~100% :(

Can u tell me, please, is it possible that problem may be in the dupplex mode? I've tried to use full and half on 10 mbit/s
and 100 mbit/s 

And again, many thanks for your attention!!!


17.03.2010, в 21:41, Gianluca Varenni написал(а):

> WinPcap is optimized for packet capture, at the expense of a jitter 
> introduced from the time the packet is received by the driver to the time 
> the packet is received by the user application. This means that the packet 
> is received by the driver and timestamped, saved into a kernel buffer and 
> later retrieved by the winpcap-based application. You can reduce this delay 
> by playing with the timeout and mintocopy values (they are both accessible 
> through the WinPcap API), obviously at the expense of the CPU load.
> 
> Have a nice day
> GV
> 
> 
> 
> --------------------------------------------------
> From: "Alimjan Kuramshin" <alimjankuramshin at gmail.com>
> Sent: Wednesday, March 17, 2010 11:32 AM
> To: <winpcap-users at winpcap.org>
> Subject: Re: [Winpcap-users] Packets capture latency
> 
>> Hello, Gianluca!
>> 
>> Thank you, for your attention and reply.
>> 
>> Well, and within Wireshark too (but this is not quite correct place for 
>> that).
>> 
>> When i receive one packet from my device i'm emmideatly send back received 
>> packet back(for testing)
>> and using oscilloscope watch for my laptop ethernet card TX+ and TX- pins.
>> 
>> Also, i've tried to use different handles(pcap_open) for capturing/sening 
>> data, no changes the same result. :(
>> 
>> 17.03.2010, в 20:06, Gianluca Varenni написал(а):
>> 
>>> What is the original delay between the packets?
>>> 
>>> Are you looking at the timestamps with wireshark?
>>> 
>>> Have a nice day
>>> GV
>>> 
>>> --------------------------------------------------
>>> From: "Alimjan Kuramshin" <alimjankuramshin at gmail.com>
>>> Sent: Wednesday, March 17, 2010 9:58 AM
>>> To: <winpcap-users at winpcap.org>
>>> Subject: [Winpcap-users] Packets capture latency
>>> 
>>>> Hello, everyone! My name is Alimjan and i'm developing custom board with
>>>> the ethernet device and i've got some problem
>>>> with capturing data from it ..
>>>> 
>>>> I'm using Notebook Asus G1S with Windows XP + SP3 installed to connect 
>>>> to
>>>> my board. Using WinPcap(4.1.1), i'm capture data from the board. So, 
>>>> i've
>>>> found that delay between the captured packets is a very 'vary' i mean 
>>>> that
>>>> it has huge spread, e.g,
>>>> at 10 mbits/s i've got 45-70 us delay, it is normal i gues, but some 
>>>> times
>>>> this delay grow up to 3-7 ms (milliseconds), for example, distance 
>>>> between
>>>> packets: 45 us, 46 us, 50 us, 47 us and so on.. then
>>>> 4 ms, 7 ms, 1 ms, and then again 53 us, 47 us and so on, the repeat...
>>>> Number of 'normal' delay is also very 'vary', delay may appear in a
>>>> different numbers of received packets, no logic :(
>>>> 
>>>> My laptop is directly connected to my board e.g. cross TX->RX, RX->TX, 
>>>> no
>>>> hubs or something. Also using oscilloscope connected to the  TX+ and TX-
>>>> lines i've found that it is no delay between packet that my custom board
>>>> (device) have send.  Anybody please, help me to solve this situation,
>>>> may be i'm doing something wrong?
>>>> 
>>>> P.S. i'm using winpcap exapmle code to capture the packets with callback
>>>> method and within pcap_next_ex.
>>>> 
>>>> P.P.S i'm sorry for my english spelling skill, i hope that you can
>>>> understand my.
>>>> 
>>>> Many thanks, bye..
>>>> 
>>>> _______________________________________________
>>>> Winpcap-users mailing list
>>>> Winpcap-users at winpcap.org
>>>> https://www.winpcap.org/mailman/listinfo/winpcap-users
>>> 
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>> 
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