The PFC is capable of the same things as a DFC, just in a centralized manner. So, for example, CoPP works just fine in hardware with a PFC - you don't NEED to offload the QoS to the LCs. You need a DFC only if some resources are close to exhaustion (like pps rates supported by centralized forwarding, netflow entries, QoS entries and so on).
On Wed, 2 Sep 2009, Justin Shore wrote: > You eluded to one of my strongest selling points on DFCs though I don't > think you made that particular connection yet. DFCs offload QoS to the > LC as you said. That also means that CoPP is also handled in hardware > if you have DFCs in place since it requires MLS QoS on that platform. > Ie, if your 6500/7600 is going to be publicly-accessible on the Internet > in any capacity and you want it to be able to use CoPP to withstand a > targeted DoS attack then DFCs are not optional, they're critical. > > The others on the list can probably give you much more in-depth views on > the other aspects of the card but I found CoPP to be a big enough > selling point. It wouldn't be good is a simple little DoS attack took > down my core 7600s. > > Justin > > > Alan Buxey wrote: > > hi, > > > > okay, from the background of I know what the DFC is and how it > > operates etc... i know I want them - however, I need to justify > > the upgrade/part cost to sort out a couple of 6500's. in some of > > our 6500's, the 10G blades have DFCs already...but several 6724's dont > > (they just have CFC). ...as i said, I want them, but need to get > > some management/funding buy-in - and they dont want the 'what it > > does' information - they want some hard and fast facts that Cisco dont > > sem to want to tell me ..... so, the question is > > > > 1) is there any way of showing the sup720 strain/utilisation...particularly > > is there a way of showing DFC usage on the blades where we have them? > > > > 2) it offloads IPv6 and QoS - we're into both of those (and more so over the > > next year) - any particular insights into QoS performance/issues without > > DFC ? any throughput figures for IPv6 ? > > > > (i know that with CFC we're limited to the backplane (32mpps?) and we get ~ > > 48mpps > > per blade with DFC) > > > > ...or could it be that DFC's are only really useful to a particular > > deployment > > and I just *think* i need them? ;-) > > > > alan > > _______________________________________________ > > cisco-nsp mailing list [email protected] > > https://puck.nether.net/mailman/listinfo/cisco-nsp > > archive at http://puck.nether.net/pipermail/cisco-nsp/ > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
