[Winpcap-users] Packets capture latency

Wed Mar 17 12:14:45 PDT 2010

Thank you a lot for that point, i'll try it. I've used only a pair combination of the
PCAP_OPENFLAG_PROMISCUOUS and PCAP_OPENFLAG_NOCAPTURE_LOCAL flags..

A little addition: in my project i have to (and should) send a small packets of data 60..200 bytes  throw my
ethernet interface, may be in this place i've got mess?! I'm clearly understand that winthin this(60..200) payload i'll not
reach full band usage..

Gianluca, Thank you a lot!

17.03.2010, в 22:01, Gianluca Varenni написал(а):

> 
> 
> --------------------------------------------------
> From: "Alimjan Kuramshin" <alimjankuramshin at gmail.com>
> Sent: Wednesday, March 17, 2010 11:51 AM
> To: <winpcap-users at winpcap.org>
> Subject: Re: [Winpcap-users] Packets capture latency
> 
>> 
>> :(
>> 
>> 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% :(
> 
> Please look at the sample UserLevelBridge. It uses a couple of flags that 
> should help you.
> 
>> 
>> 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
> 
> Full or half duplex is definitely not the problem.
> 
> Have a nice day
> GV
> 
>> 
>> 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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