Comment by antithesis-nl

Comment by antithesis-nl 2 days ago

3 replies

As far as I can tell, Software Defined Networking (which this is about: "P4 is a domain-specific language for network devices") by now is pretty much a decade-old promise that never materialized. I'd still love to be wrong though!

So, let's take the next paragraph: "Before P4, vendors had total control over the functionality supported in the network (...) controlled the rollout of new features (e.g., VXLAN), and rollouts took years"

Anyone has a pointer to any actually available hardware capable of L2 and L3 packet processing where I could have implemented VXLAN in, say, weeks using P4? Again, as far as I can tell, it's all either killed-off-a-long-time-ago, "contact us" vaporware, or exotic 40/100-Gb-only Top-o-Rack gear, and even for those, there is nary an "add to cart" button in sight...

wmf 2 days ago

P4 is used by Cisco Silicon One, Xsight, AMD Pensando, Intel Mount Evans, etc. "Contact us" isn't the same thing as vaporware; the Pensando SSDK and Intel ES2K SDE definitely exist for example. I realize it sucks when things aren't available to hobbyists but it's a mistake to pretend it's fake.

P4 is really only needed in data center networks because slower campus/home networks can usually get away with software processing and their lower prices probably can't support the R&D of a programmable architecture.

kuon 2 days ago

I would be curious as well. Every time we try something "software defined" the drawbacks are major, cost goes up, stability goes down and most importantly, bandwidth goes down by a factor 10. The only software defined networking gear we use is OpenBSD, to do some complex routing, but we cannot go above 5GB/s.