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Network Lab • • By HubInfo Research Collective • 9 min read

Media CDN Latency Report: Edge PoP Round-Trips, Cache Hit Rates & Regional Throughput

Quarterly lab measurements comparing edge point-of-presence performance across major delivery networks — with real RTT numbers and cache-hit analysis.

Streaming quality is determined less by raw bandwidth than by where the bits come from. A portal serving video from an edge node 15 milliseconds away will always feel faster than one pulling segments from an origin 200 milliseconds away — regardless of how fast the user’s last-mile connection is.

This quarter we probed delivery behavior across three regions and twelve vantage points. Here’s what the data showed.

Edge RTT: The Single Biggest Predictor of Playback Quality

Vantage Point      │ Edge RTT (median) │ TTFF Impact
───────────────────┼───────────────────┼──────────────────────────
Singapore (SG)     │   9 ms            │ Sub-1s first frame
Bangkok (BKK)      │  14 ms            │ Sub-1.2s first frame
Frankfurt (FRA)    │  11 ms            │ Sub-1.1s first frame
US-East (IAD)      │  17 ms            │ ~1.4s first frame
US-West (SJC)      │  22 ms            │ ~1.6s first frame
Rural 4G fallback  │  85 ms            │ 3–5s, noticeable delay

The pattern is unambiguous: every 10ms of edge RTT adds roughly 100–150ms to time-to-first-frame once TCP/TLS handshakes and manifest round-trips compound.

Cache Hit Ratio vs. Segment Churn

We tracked cache behavior via X-Cache / CF-Cache-Status response headers on identical manifest and segment requests:

  • High-hit portals (>95%): popular title segments stay resident at the edge; cold-start latency only hits the first viewer per region.
  • Low-hit portals (<80%): long-tail content constantly evicts, forcing origin pulls that double TTFF and introduce jitter during peak hours.
Well-tuned edge:   Origin ──► Shield PoP ──► Edge PoP ──► Viewer
                        (once)        (cached, reused by thousands)

The Shield-Layer Pattern

Best-performing networks insert a mid-tier “shield” cache between origins and edge PoPs. When 200 edge nodes all miss the same segment simultaneously, the shield absorbs the thundering herd — the origin sees one request instead of 200.

What We Measure Going Forward

Our rolling dataset now tracks per-portal edge distribution and miss-rates continuously. Full regional maps and per-network scorecards are published at Media CDN Performance Database & Edge Latency Maps.

Key Findings

  1. Portals using multi-CDN failover showed 40% lower p99 stall rates than single-CDN deployments.
  2. HTTP/3 (QUIC) adoption correlated with measurably better performance on mobile networks subject to NAT rebinding.
  3. Portals pinning Cache-Control: immutable on versioned segment URLs achieved the highest edge residency.