Modern CPUs could push a lot of PPS, but they can't with current network stacks. Linux or FreeBSD on a modern 3.5ghz octal core Xeon can't push enough 64 byte packets to saturate a 100Mb link. PFSense 3.0 was looking to use dpdk to do line rate 40Gb, but they are also looking at alternatives like netmap. PFSense 3.0 is also aiming to do line rate 10Gb+ and eventually 40Gb VPN/IPSec, which dpdk would make viable. There's also talk about potentially scaling line rate all the way into the 80Gb range. That's full stateful firewalling and NAT.

I just hope someone can fix the network stacks so they can actually handle a 10Mb/s DDOS attacks. There is no reason 10Mb of traffic should take down a modern firewall. Turns out to be around 1 million clock cycles per packet. What the heck is the network stack doing to spend 1mil cycles trying to handle a packet? /rant

On Fri, Feb 12, 2016 at 2:40 AM, Mikael Abrahamsson <swmike@swm.pp.se> wrote:
On Thu, 11 Feb 2016, Dave Täht wrote:

Someone asked me recently what I thought of the dpdk. I said:
"It's a great way to heat datacenters". Still, there's momentum it
seems, to move more stuff into userspace.

 Especially now that Intel CPUs seem to be able to push a lot of PPS compared to what they could before. A lot more.

What one has to take into account is that this tech is most likely going to be deployed on servers with 10GE NICs or even 25/40/100GE, and they are most likely going to be connected to a small buffer datacenter switch which will do FIFO on extremely small shared buffer memory (we're talking small fractions of a millisecond of buffer at 10GE speed), and usually lots of these servers will be behind oversubscribed interconnect links between switches.

A completely different use case would of course be if someone started to create midrange enterprise routers with 1GE/10GE ports using this technology, then it would of course make a lot of sense to have proper AQM. I have no idea what kind of performance one can expect out of a low power Intel CPU that might fit into one of these...

--
Mikael Abrahamsson    email: swmike@swm.pp.se
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