How TCP/IP Sockets Work — Animated Data Path

The traditional kernel networking path for the same message transfer — the counterpart to the RDMA animation. Watch the data get copied twice, processed by the CPU at every layer, and interrupt the remote CPU. RDMA skips all of it.

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Payload data Memory copy (CPU) TCP processing IP processing DMA transfer On the wire Interrupt (IRQ) ACK

Key idea: every byte is copied between user space and the kernel (twice) and touched by the CPU at each protocol layer. The kernel sits on the data path, send()/recv() cause context switches, and inbound packets interrupt the CPU. RDMA removes all of this with kernel bypass, zero-copy DMA, and one-sided operations. ←/→ step · Space play/pause.