gettys-bufferbloat
Jim Gettys Bufferbloat Style Guide
Overview
Jim Gettys, while working at Bell Labs and later on the One Laptop per Child project, discovered and named "bufferbloat"—the phenomenon where excessive buffering in network equipment causes massive latency spikes. Modern networks often have seconds of buffering, destroying interactive performance even when bandwidth is plentiful. Gettys' crusade to fix bufferbloat led to fq_codel and the understanding that network latency under load is the true measure of network quality.
Core Philosophy
"Latency is the new bandwidth. We have plenty of bandwidth; what we lack is low latency."
"The buffer is full of lies. Every packet in that buffer is a broken promise about when it will arrive."
"Good networks feel fast. Bufferbloated networks feel like wading through molasses."
Gettys realized that optimizing for throughput while ignoring latency creates terrible user experience. A network with 100ms idle RTT that spikes to 2000ms under load is fundamentally broken, even if it achieves high throughput. The solution is to keep queues short and managed.
Design Principles
- Latency Under Load Matters: Measure RTT while the network is busy, not idle.