The Science of Acceleration
Short definitions used across NetDNA products and support. One URL per term so each can rank.
- CDN — A content delivery network copies files from your origin to servers closer to users so pages load faster. NetDNA EdgeCaching is the HTTP CDN product.
- PoP — A point of presence is a NetDNA edge location. Traffic is routed to the nearest healthy PoP over Anycast DNS.
- Anycast DNS — Anycast advertises the same IP from many PoPs. The internet picks the closest announcement, which is how NetDNA Global Anycast DNS works.
- Origin shield — A shield PoP sits in front of your origin so only one edge region fetches misses. This cuts origin load during cache stampedes.
- Cache hit ratio — The share of requests served from cache without touching origin. Raise it with long TTLs, correct Cache-Control, and EdgeRules.
- TTL — Time to live is how long an object may stay in cache. Set it with Cache-Control max-age or NetDNA zone defaults.
- Signed URLs — A signed URL expires and cannot be hotlinked. EdgeSecurity uses token authentication and secure links for paid or private files.
- Pull zone — A pull zone fetches files from your origin on first miss, then caches them. Best for websites, WordPress and Magento.
- Push zone — A push zone stores files you upload (FTP/API). Best for large libraries, software downloads and video mezzanines.
- VOD zone — A video-on-demand zone caches progressive or streaming video. Pair with HDDN for high-definition delivery.
- Live zone — A live zone ingests a stream and fans it out to viewers from the edge. Used for events and 24/7 channels.
- Edge SSL — SSL terminated at the CDN PoP so HTTPS never travels extra hops to origin. That is EdgeSSL.
- Cache-Control — The HTTP header that tells NetDNA and browsers how long to keep a file. See the cache-headers guide.
- Cache purge — Purge removes an object so the next request refetches origin. Use the control panel or REST API.