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List:       ntop-dev
Subject:    Re: [Ntop-dev] [Ntop-misc] Introducing PF_RING DNA (Direct NIC
From:       Luca Deri <deri () ntop ! org>
Date:       2010-02-22 21:10:10
Message-ID: A07B75FE-9253-44FF-A0A9-F78F1DE76AC7 () ntop ! org
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Beyers
this code is released as GPL in source format. As usual, as this is self-funded \
research, I ask a little help for running the project as with TNAPI, this unless the \
requestor is also a researcher.

Thanks Luca

On Feb 22, 2010, at 10:15 AM, Beyers Cronje wrote:

> Great stuff, thank you Luca!
> 
> Is DNA available for free as with PF_RING, or is there a license associated with it \
> as with TNAPI ? 
> Kind regards
> 
> Beyers Cronje
> 
> On Sun, Feb 21, 2010 at 10:15 PM, Luca Deri <deri@ntop.org> wrote:
> Dear all,
> this is to announce the availability of PF_RING DNA (Direct NIC Access) that \
> significantly increments performance (up to 80%) when compared with Linux packet \
> capture and PF_RING (non DNA). 
> PF_RING is polling packets from NICs by means of Linux NAPI. This means that NAPI \
> copies packets from the NIC to the PF_RING circular buffer, and then the userland \
> application reads packets from ring. In this scenario, there are two pollers, both \
> the application and NAPI and this results in CPU cycles used for this polling; the \
> advantage is that PF_RING can distribute incoming packets to multiple rings (hence \
> multiple applications) simultaneously. 
> PF_RING DNA (Direct NIC Access) is a way to map NIC memory and registers to \
> userland so that packet copy from the NIC to the DMA ring is done by the NIC NPU \
> (Network Process Unit) and not by NAPI. This results in better performance as CPU \
> cycles are used uniquely for consuming packets and not for moving them off the \
> adapter. The drawback is that only one application at time can open the DMA ring, \
> or in other words that applications in userland need to talk each other in order to \
> distribute packets. 
> In a nutshell if you like flexibility you should use PF_RING, if you want pure \
> speed PF_RING DNA is the solution. Please note that in DNA mode NAPI polling does \
> not take place, hence PF_RING features such as reflection and packet filtering are \
> not supported. 
> For more information, please have a look at the PF_RING home page \
> (http://www.ntop.org/PF_RING.html). As of today DNA support is available only for \
> Intel 1 Gbit PCI Express (e1000e family) cards. 
> Luca
> 
> 
> ---
> 
> "Debugging is twice as hard as writing the code in the first place. Therefore, if \
> you write the code as cleverly as possible, you are, by definition, not smart \
> enough to debug it. - Brian W. Kernighan 
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---
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