The Tealium Multi-CDN infrastructure (mCDN) is designed to deliver files to our customers' websites as quickly and reliably as possible. The mCDN leverages multiple content delivery networks (CDNs) in real-time to determine the fastest delivery node in the respective geographic region.

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How mCDN Works

The mCDN is responsible for the delivery of all files from the domain. This includes the main iQ Tag Management loader file, utag.js, all tag loader files (utag.#.js), and any hosted data layer files.

  1. A web page with Tealium's JavaScript library (utag.js) installed makes a request to
  2. The local DNS server instructs the browser to contact DynDNS to resolve the host.
  3. DynDNS uses Cedexis to select the best performing CDN.
  4. Cedexis uses last mile data coupled with the requesting browser's geographic location to determine which CDN performs best and directs the browser to that CDN.
  5. The selected CDN responds with the requested file.