Live media distribution systems and methods enable scalable and efficient caching of live media content over computer networks. A live media backend generates video fragments for distribution to a content delivery network. The content may originally be streamed live by a live media source. The live media backend determines priority information for the video fragments and attaches a priority identifier to a data envelope for the video segments. The video fragments with the attached priority identifier are sent to a content delivery network. The content delivery network can access the attached priority identifier without analyzing the content of the video fragment to enable intelligent caching of video segments within the media distribution system.