The control plane can be a raspberry pi. Its what allows you to modify the rules how you route. Its the interface.

The data plane is where you have high speed logic and data traveling. That's where you do the multiple 100GBps software defined networking, and its crazy fast chips doing it.

And the control plane has interconnects to program the data plane chips to the rules you want. So the data never hits the control plane at all. Its kind of like a water faucet where the knob doesn't touch the water but controls the floodgates.

That may be the case now, but ages ago it was just a fancy BSD box as far as I could tell. I used to be a reseller for their product circa 2000 and I wasn't aware of any proprietary hardware inside, just a really lean networking stack.

We were getting slammed on duty for the product and we were looking at ways of getting the appliances built locally using licensed F5 software, as the software itself wasn't as heavily taxed as the physical hardware. Everything in it seemed fairly commodity, except for the big F5 logo on the front.

It was an appliance that worked fantastically well. One deployment had an uptime of over ten years.

It's not about that. FPGAs behind engineering solution to digest packets at big PPS behind interface is what it does.

You know, Cisco's IOS XR is built on Linux, but all the real parts are behind their private kernel modules running on ASICs and FPGAs, traffic doesn't even touches the TCP/IP stack of the OS. Cisco ASAs have Celeron/Atom CPUs which obviously couldn't hold the specified loads.