It's time to replace TCP in the datacenter (2023)

> Although Homa is not API-compatible with TCP,

IPv6 anyone? People must start to understand that "Because this is the way it is" is a valid, actually extremely valid, answer to any question like "Why don't we just switch technology A with technology B?"

Despite all the shortcomings of the old technology, and the advantages of the new one, inertia _is_ a factor, and you must accept that most users will simply even refuse to acknowledge the problem you want to describe.

For you your solution to get any traction, it must deliver value right now, in the current ecosystem. Otherwise, it's doomed to fail by being ignored over and over.

Also there needs to be a big push to educate people on <new thing>. I know TCP very well, it would need quite a lot of incentive for me to drop that for something I don't yet understand as well. TCP was highly beneficial which is why we all adopted it in the first place, whatever is to replace it needs to be at least that beneficial...which will be a tall order.

I'd say that usually it's not about the balance of advantages but the balance of pain. You go through the pains of switching to a new and unfamiliar solution if your current solution is giving you even more pain.

If you don't feel much pain, you can and should stay with your current solution. If it's not broken, or not broken badly enough, don't fix it by radical surgery.

> inertia _is_ a factor

why would inertia be a factor? If I want to support protocol ABC in my data center, then I buy hardware that supports protocol ABC, including the ability to down shift to TCP when data leaves the data center. We aren't talking about the internet at large so there is no need to coordinate support with different organizations with different needs.

Google, could mandate you can't buy a router or firewall that doesn't support IPv6. Then their entire datacenter would be IPv6 internally. The only time to convert to IPv4, would be if the local ISP doesn't support v6.

But tcp/ipv6 is API compatible with tcp/ipv4? You can even accept ipv4 connections to a ipv6 listening socket if you have a ipv4 address assigned. The issue is ipv4 is not forward binary compatible with ipv6 because you can't fit more than 2^32 addresses in a ipv4 packet.

But yeah if you are a large bloated enterprise like amazon or microsoft that owns large amounts of ipv4 address space and expensive ipv4 routing equipment there is not a ton of value in switching