  In spite of its long and successful history, TCP is a poor transport protocol
for modern datacenters. Every significant element of TCP, from its stream
orientation to its expectation of in-order packet delivery, is wrong for the
datacenter. It is time to recognize that TCP's problems are too fundamental and
interrelated to be fixed; the only way to harness the full performance
potential of modern networks is to introduce a new transport protocol into the
datacenter. Homa demonstrates that it is possible to create a transport
protocol that avoids all of TCP's problems. Although Homa is not API-compatible
with TCP, it should be possible to bring it into widespread usage by
integrating it with RPC frameworks.
