jsDelivr's answer:
jsDelivr is the only free CDN that aims to be production ready even for the most critical workloads. It has multiple failover systems for all of its components to ensure 100% uptime and uses multiple CDNs and datacenters for better performance.
Cisco SD-WAN - SD-WAN is a software-defined approach to managing the wide-area network, or WAN.
cdnjs - An open source community driven JS/CSS CDN.
CloudFlare - Cloudflare is a global network designed to make everything you connect to the Internet secure, private, fast, and reliable.
Amazon CloudFront - Amazon CloudFront is a content delivery web service.
KeyCDN - KeyCDN is a high-performance Content Delivery Network (CDN). Lowest price globally at $0.04/GB with HTTP/2 Support and free Origin Shield.
Cisco Meraki SD-WAN - What is SD-WAN?