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 <[email protected]> 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 > > _______________________________________________ > Ntop-misc mailing list > [email protected] > http://listgateway.unipi.it/mailman/listinfo/ntop-misc >
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