Two Weeks Later: Finding and Eliminating Long Tail Latencies

This post details Cloudflare's efforts to improve network performance in 61 country/network pairs where latency exceeded 100ms behind the leading provider. It explains how Cloudflare identified these issues through benchmarking and then implemented specific technical solutions, including rectifying route advertisement in Brazil by rerouting traffic from a transit provider to a private network interconnect (PNI) via their backbone, establishing new peering sessions in Spain to keep traffic local, and optimizing upstream selection in Africa by adjusting BGP LOCAL_PREF values to prefer a transit provider over a private peer for specific network prefixes. The post quantifies the improvements, showing Cloudflare becoming the #1 network in 29 of these pairs and significantly improving performance in almost all of them.