🐢

Nagle's Algorithm & TCP_NODELAY

Simple

Free preview · 2 of 4 steps

Nagle's algorithm: coalesce small writes

In 1984, network congestion was caused by 'tinygram' problem: applications sending many 1-byte TCP segments (telnet, each keystroke). Nagle's algorithm buffers small writes in the kernel until either an MSS-sized segment is assembled or the previous segment is acknowledged.

This reduces packet count dramatically on slow WAN links — but introduces latency.

Packets in motion — click to inspect:

1 / 2

Space to play/pause · ← → to step