3.1 Global Edge Delivery: CloudFront & AWS Global Accelerator

🎯 Key AWS SAA-C03 Architectural Takeaways

• Amazon CloudFront caches static and dynamic HTTP/HTTPS content at global edge locations, reducing origin latency and offloading server bandwidth.
• AWS Global Accelerator uses Anycast static IP addresses to onboard TCP/UDP traffic at the nearest edge location, routing traffic over the private AWS global network backbone.
• CloudFront Origin Shield acts as a centralized caching layer between regional edge caches and your origin, minimizing origin load for high-demand streaming assets.
• Use CloudFront for web applications requiring content caching (HTML, media, APIs); use Global Accelerator for gaming, VoIP, IoT, and non-HTTP TCP/UDP protocols.

Delivering low-latency experiences to global users requires positioning content and network ingress close to the edge. Amazon CloudFront operates hundreds of Edge Points of Presence (PoPs) connected via private AWS fiber. CloudFront terminates TCP/TLS handshakes at the edge, caches static and dynamic web assets, and compresses payloads using Gzip and Brotli.

To optimize origin offload for viral media and live streaming, architects deploy CloudFront Origin Shield. Origin Shield acts as a consolidated central cache between regional edge caches and the origin server. When thousands of global viewers request a video segment, all regional edge caches query Origin Shield rather than hitting the origin directly, dramatically increasing cache hit ratios and protecting backend infrastructure.

For workloads that do not use HTTP/HTTPS or require fixed IP addresses, AWS Global Accelerator provides edge routing. Global Accelerator assigns two static Anycast IPv4 addresses. Client traffic hits the nearest AWS edge location and traverses AWS's congestion-free private fiber backbone directly to Application Load Balancers, Network Load Balancers, or EC2 instances.

Global Accelerator is uniquely suited for real-time multiplayer gaming, voice-over-IP (VoIP), financial FIX protocols, and IoT data ingestion because it optimizes TCP and UDP routing, bypasses public internet BGP congestion, and executes endpoint health failover in under 10 seconds.

⚠️ Common Pearson VUE / AWS Exam Traps

• Attempting to route UDP traffic through Amazon CloudFront — CloudFront only supports HTTP, HTTPS, and WebSocket protocols; Global Accelerator handles UDP/TCP.
• Using Route 53 latency routing instead of Global Accelerator when instant failover (< 10 seconds) is required — Route 53 relies on client DNS TTL expiration.
• Forwarding unnecessary cookies or query strings to CloudFront origins, which fragments the cache key and destroys cache hit ratios.