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Models for adaptive -streaming-aware CDNI - Content Acquisition and Content Collections draft -brandenburg-cdni-has- 01, section 3.2. CDNI Extended Design Team Meeting Virtual Meeting May 29, 2012 Ray van Brandenburg (ray.vanbrandenburg@tno.nl).
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Models for adaptive-streaming-aware CDNI-Content Acquisitionand Content Collectionsdraft-brandenburg-cdni-has-01, section 3.2 CDNI Extended Design Team Meeting Virtual Meeting May 29, 2012 Ray van Brandenburg (ray.vanbrandenburg@tno.nl)
Key Considerations regarding Content Acquisition • Content Collection may consists of very large number of files (e.g. 100s to 1000s) • Large numbers of files increases transaction overhead when acquiring content from uCDNby dCDN • Lots of very small transactions instead of single big one
Option 2.1: “Do-Nothing” Approach - 1 • Assumes no HAS awareness in uCDN/dCDN and no additions to CDNI Interfaces • Result: the dCDN will acquire each file as a separate independent chunk • i.e. 1000 chunks results in 1000 content acquisition transactions between dCDN and uCDN
Option 2.1: “Do-Nothing” Approach - 2 Effect on CDNI Interfaces: • None Advantages/Drawbacks: + Extremely flexible, dCDN only acquires chunks that are necessary - Creates more transaction overhead between dCDN and uCDN - More latency for first client requesting a particular chunk from dCDN
Option 2.2: “Allow single file acquisition of fragmented content” - 1 • Might be useful to allow dCDN to acquire the entire Content Collection in one transaction • Either as part of a single file (fragmented content), or • As a folder of files, or • As a compressed file containing all chunks • Requires HAS awareness in both dCDN and uCDN
Option 2.2: “Allow single file acquisition of fragmented content” - 2 Effect on CDNI Interfaces: • CDNI Metadata Interface: Add fields for indicating the particular type of HAS (e.g. MPEG DASH or HLS) that is used and whether segments or fragments are used • CDNI Metadata Interface: Add field for indicating the name and type of the manifest file(s) Advantages/Drawbacks: + Allows for more efficient content acquisition in all HAS-specific supported forms - Creates bandwidth and storage overhead in case where clients only request a very small portion of the available chunks • Requires full HAS awareness on part of dCDN/uCDN • Requires significant CDNI Metadata Interface extensions