The graphs show near 100% CPU usage at small packet sizes, and low PPS. That would lead to a pretty easy to launch DDoS against a software based router platform. Since there isn't a separation between control plane/forwarding plane, an attacker could trivially take you offline. I'd imagine due to the nature of x86 platform, being interrupt based and forwarding table residing in memory the CPU has to access, theres a finite amount you can scale this without risking big disruptions from a relatively small DDoS.
Not saying software platforms can't achieve good throughput, there has to be a realization of the limits of the platform, and when it shouldn't be used. Again, I personally use the Vyatta commercial software, and it works great, so I'm not knocking it. But I wouldn't consider it high-end performance when a few million PPS can lead to service disruptions.
-- Brent Jones brent@servuhome.net
Every tool has its use. Also, they have several different sized appliances. How much CPU use you get depends on how many cores you throw at the problem. They can use multiple cores/processors. The result given in one test might not match someone else's test if they have higher end hardware, maybe better than the appliances Vyatta ships. But the primary point I am trying to make is if you have an office with sub-gigabit connectivity and you need NAT and firewalling and VPNs, it might be a very cost-effective solution. It might not be a good solution in a different environment. It is sort of like pointing out that your neighbor's Accord doesn't have the performance characteristics of a Ferrari but your neighbor only drives in rush hour on roads with a maximum speed of 65 MPH. The Ferrari would cost much more money, cost more to support over time, and not get him to work any faster. If one is never going to pass enough traffic to get anywhere near the maximum performance of the unit anyway, why spend so much more money? Besides, on most integrated firewall/NAT/VPN units I have used in the past, I have run them out of CPU from VPN and NAT long before they ever reached their maximum traffic throughput.