Investigating Web Content Delivery Performance over Starlink
Rohan Bose, Jinwei Zhao, Tanya Shreedhar, Jianping Pan, Nitinder Mohan
TL;DR
This paper addresses how Starlink's LEO network affects web content delivery by decomposing end-to-end latency across PoP, DNS, and CDN layers. It leverages a two-year, multi-layer measurement campaign combining Cloudflare AIM, M-Lab, RIPE Atlas probes, and controlled Starlink vantage points to quantify satellite and terrestrial contributions to latency. The study identifies three performance regimes driven by infrastructure density, demonstrates that PoP proximity often dominates, and reveals that DNS/CDN misalignment and cache misses can cause large penalties, particularly in Africa. It shows that strategically relocating PoPs yields substantial gains where CDN maturity is low, and it argues for satellite-aware request mapping and potential in-orbit caching, with open data and code to support reproducibility and future work.
Abstract
Low Earth Orbit (LEO) satellite ISPs promise universal Internet connectivity, yet their interaction with content delivery remains poorly understood. We present the first comprehensive measurement study decomposing Starlink's web content delivery performance decomposed across Point of Presence (PoP), DNS, and CDN layers. Through two years of measurements combining 225K Cloudflare AIM tests, M-Lab data, and active probing from 99 RIPE Atlas and controlled Starlink probes, we collect 6.1M traceroutes and 10.8M DNS queries to quantify how satellite architecture disrupts terrestrial CDN assumptions. We identify three distinct performance regimes based on infrastructure density. Regions with local content-rich PoPs achieve near-terrestrial latencies with the satellite segment dominating 80-90% of RTT. Infrastructure-sparse regions suffer cascading penalties: remote PoPs force distant resolver selection, which triggers CDN mis-localization, pushing latencies beyond 200 ms. Dense-infrastructure regions show minimal sensitivity to PoP changes. Leveraging Starlink's infrastructure expansion in early 2025 as a natural experiment, we demonstrate that relocating PoPs closer to user location reduces median page-fetch times by 60%. Our findings reveal that infrastructure proximity, not satellite coverage, influences web performance, requiring fundamental changes to CDN mapping and DNS resolution for satellite ISPs.
