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.

翻译：低地球轨道（LEO）卫星互联网服务提供商（ISP）有望实现全球互联网覆盖，然而其与内容交付网络（CDN）的交互机制尚不明确。本研究首次通过综合测量分析，从接入点（PoP）、域名系统（DNS）和CDN三个层面解构Starlink的网页内容交付性能。通过为期两年的测量工作，结合22.5万次Cloudflare AIM测试、M-Lab数据，以及来自99个RIPE Atlas探测点和受控Starlink探测器的主动探测，我们收集了610万条路由追踪数据和1080万次DNS查询记录，以量化卫星架构如何颠覆地面CDN的传统假设。根据基础设施密度，我们识别出三种不同的性能模式：在拥有本地化内容密集型PoP的区域，网络延迟接近地面水平，卫星段占往返时间（RTT）的80-90%；基础设施稀疏区域则承受级联性能损失——远程PoP导致远端解析器被选择，进而引发CDN定位错误，使延迟超过200毫秒；基础设施密集区域对PoP变更表现出极低的敏感性。借助2025年初Starlink基础设施扩张这一自然实验，我们证明将PoP迁移至更接近用户的位置可使页面获取时间中位数降低60%。研究结果表明，影响网页性能的关键因素是基础设施邻近度而非卫星覆盖范围，这要求针对卫星ISP的CDN映射与DNS解析机制进行根本性变革。