[Winpcap-users] Winpcap and NIC chipsets

[Stefano Bonetti]

Dear Fulvio,
many thanks for your advice.

Best,
Stefano


Il 11/06/13 10:30, Fulvio Risso ha scritto:
> Dear Stefano,
> the behaviour you're observing is well-known. Sometimes it depends on 
> the chipset, some other times it depends on the quality of the NIC 
> drivers.
> In either case, there's nothing you can do to bypass those issues in 
> WinPcap.
> The best solution is to replace the NIC.
> Another possible solution is to use some accelerated NIC driver in 
> order to bypass the Operating system, hence decreasing the overhead. 
> However, again, those are usually able to operate only on a few NICs, 
> and usually those are high quality NICs.
> I'm not aware of those (free) drivers in Windows; probably something 
> exist that does not come for free.
> In Linux/FreeBSD you can use netmap, or pf_ring/DNA (linux only).
>
>     fulvio
>
>
> On 11/06/2013 08:57, Stefano Bonetti wrote:
>> Hi all,
>> we are using the Winpcap library inside a low-latency audio/visual
>> streaming system named "LoLa"
>> (http://www.conts.it/artistica/lola-project/lola-low-latency-audio-visual-streaming-system). 
>>
>>
>> More precisely we are using Winpcap to send about 55300 packet per
>> second with the pcap_sendqueue_queue and pcap_sendqueue_transmit
>> commands; each packet is 1000 bytes in size and the Lan speed is 1Gbit.
>> The system performs very well (so thanks for you great job) but we have
>> noticed a different behavior using
>> some network adapters. With the Realtek or Marvell chipsets we are able
>> to send/receive only half of the packets,
>> but when we use Intel NICs we are able to send and receive all the
>> packets (no drops and with the network monitor
>> showing, correctly, 98% of utilization); for our project it means that
>> we are sending/receiving a video stream at
>> 60fps (uncompressed RGB, 24bit, 640x480).
>> The Intel chipsets are 82574 and 82579 … we have tested many computers
>> with the same result and the same
>> behavior occurs even using the MS Winsock libraries, so it does not seem
>> to be a problem related specifically to
>> the winpcap library but generally to the NICs chipset.
>>
>> Has someone had similar experiences in the past or perhaps some
>> suggestions on how to improve the network
>> performance for Realtek/Marvell (or generally "low-cost") network 
>> chipset?
>>
>> Thanks in advance,
>> Stefano Bonetti
>> LoLa team developer
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