RDMA

Remote Direct Memory Access — a technique, not a protocol. What it does, why it exists, and the verbs API that applications program against. The two protocols that implement RDMA on the wire are InfiniBand and RoCE v2 — each gets its own section after this one.

📄️What RDMA Actually Does

RDMA is a technique, not a protocol. What it does, the TCP path vs the RDMA path, the three operations (SEND, READ, WRITE), and what the CPU actually does.

📄️Verbs, Queue Pairs, Memory Regions

The RDMA API the app actually programs against. Queue pairs, memory regions, work requests, completion queues — and how they all fit together.