DIGITAL CONTENT DISTRIBUTION SYSTEM AND METHOD

• US 20110016225A1
• Filed: 07/16/2009
• Published: 01/20/2011
• Est. Priority Date: 07/16/2009
• Status: Active Grant

• Current Assignee: Netflix, Inc.
• Original Assignee: Netflix, Inc.
• Inventors: Hunt, Neil D., Park, Anthony Neal
• Granted Patent: US 8,433,814 B2
• Time in Patent Office: Days
• US Class Current: 709/234
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04N 21/238 Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams hybrid fiber coaxial [HFC] networks for downstream channel allocation for video distribution H04L12/2801; flow control in packet networks H04L47/10; real-time communication protocols in data switching networks H04L65/00; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/4392 involving audio buffer management
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer
• CPC Class Codes: H04N 21/44209 Monitoring of downstream path of the transmission network originating from a server, e.g. bandwidth variations of a wireless network arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896
• CPC Class Codes: H04N 21/4425 Monitoring of client processing errors or hardware failure
• CPC Class Codes: H04N 21/4622 Retrieving content or additional data from different sources, e.g. from a broadcast channel and the Internet web site content organization and management for information retrieval from the Internet G06F16/958; transmission by internet of broadcast information H04H60/82; stock exchange data over packet-switching network H04L12/1804; push services including data channel over packet-switching network H04L12/1859
• CPC Class Codes: H04N 21/845 Structuring of content, e.g. decomposing content into time segments
• CPC Class Codes: H04N 21/8586 by using a URL processing chained hypermedia data for information retrieval G06F16/94; information retrieval from the Internet by using URLs G06F16/955; URL in broadcast information H04H20/93; Web-based protocols H04L67/02

Abstract

One embodiment of the present invention sets forth a technique for selecting a content distribution network (CDN) comprising at least one content server, from a plurality of CDNs, and a playing digital content file from the CDN on a content player. Selecting the CDN is based on a rank order of CDNs, an assigned weight value for each CDN, and a bandwidth measured between the content player and each CDN. Advantageously, a given content player may select a CDN based on prevailing network and CDN loading conditions, thereby increasing overall robustness and reliability when downloading digital content file from a CDN.

Claims

1. A method for downloading a digital content file from a content distribution network (CDN) residing within a content distribution system, the method comprising:

receiving a CDN list from a content directory server that includes one or more CDNs residing within the content distribution system and also includes a rank and a weight for each of the one or more CDNs;

selecting a CDN from the CDN list from which to download the digital content file based on a bandwidth test, wherein the selected CDN is capable of downloading a portion of the digital content file to a content player machine at a highest bit rate associated with the content player machine or has a weighted bandwidth greater than or equal to the weighted bandwidth associated with any other CDN included in the CDN list;

launching a buffering thread configured to download digital content associated with the digital content file from the selected CDN and to store the digital content in a content buffer; and

launching a playback thread configured to play the digital content stored in the content buffer.

2. The method of claim 1, wherein the step of selecting comprises the steps of:

computing, for a first CDN in the CDN list, a first bit rate at which the first CDN can download the portion of the digital content file to the content player machine; and

determining whether the first bit rate is equal to the highest bit rate associated with the content player machine.

3. The method of claim 2, wherein the first bit rate is equal to the highest bit rate associated with the content player machine, and the step of selecting further comprises the step of selecting the first CDN.

4. The method of claim 2, wherein the first bit rate is not equal to the highest bit rate associated with the content player machine, and the step of selecting further comprises the steps of:

computing, for a second CDN in the CDN list, a second bit rate at which the second CDN can download the portion of the digital content file to the content player machine; and

determining whether the second bit rate is equal to the highest bit rate associated with the content player machine.

5. The method of claim 1, wherein no CDN in the CDN list is capable of downloading the portion of the digital content file to the content player machine at the highest bit rate, and the step of selecting comprises the steps of:

for each CDN included in the CDN list, computing a bit rate at which the portion of the digital content file can be downloaded to the content player machine; and

for each CDN included in the CDN list, computing a weighted bandwidth equal to the product of the bit rate at which the CDN can download the portion of the digital content file to the content player machine and the weight included in the CDN list for the CDN.

6. The method of claim 5, wherein a first CDN in the CDN list has a weighted bandwidth that is greater than the weighted bandwidth associated with any other CDN included in the CDN list, and the step of selecting further comprises the step of selecting the first CDN.

7. The method of claim 5, wherein two or more CDNs in the CDN list have the same weighted bandwidth, and the step of selecting further comprises the step of selecting a first CDN of the two or more CDNs that has the lowest relative rank set forth in the CDN list.

8. The method of claim 1, wherein the buffering thread is further configured to continue downloading and storing the digital content associated with the digital content file until the buffering thread encounters a quit signal indicating that a buffer under-run condition has occurred or an end-of-stream signal indicating that the entire digital content file has been downloaded and played.

9. The method of claim 8, wherein the playback thread is configured to:

continue playing the digital content stored in the content buffer until determining that the content buffer is empty; and

send the quit signal to the buffering thread, if the entire digital content file has not been played, or

send the end-of-stream signal to a content player management thread, if the entire digital content file has been played.

10. The method of claim 9, wherein the step of selecting a CDN is repeated to select a new CDN from the CDN list, if the playback thread sends the quit signal to the buffering thread.

11. The method of claim 1, wherein the digital content file comprises digital content associated with a movie or a television show.

12. A computer-readable medium including instructions that, when executed by a processing unit, cause the processing unit to download a digital content file from a content distribution network (CDN) residing within a content distribution system, by performing the steps of:

receiving a CDN list from a content directory server that includes one or more CDNs residing within the content distribution system and also includes a rank and a weight for each of the one or more CDNs;

selecting a CDN from the CDN list from which to download the digital content file based on a bandwidth test, wherein the selected CDN is capable of downloading a portion of the digital content file to a content player machine at a highest bit rate associated with the content player machine or has a weighted bandwidth greater than or equal to the weighted bandwidth associated with any other CDN included in the CDN list;

launching a buffering thread configured to download digital content associated with the digital content file from the selected CDN and to store the digital content in a content buffer; and

launching a playback thread configured to play the digital content stored in the content buffer.

13. The computer-readable medium of claim 12, wherein the step of selecting comprises the steps of:

computing, for a first CDN in the CDN list, a first bit rate at which the first CDN can download the portion of the digital content file to the content player machine; and

determining whether the first bit rate is equal to the highest bit rate associated with the content player machine.

14. The computer-readable medium of claim 13, wherein the first bit rate is equal to the highest bit rate associated with the content player machine, and the step of selecting further comprises the step of selecting the first CDN.

15. The computer-readable medium of claim 13, wherein the first bit rate is not equal to the highest bit rate associated with the content player machine, and the step of selecting further comprises the steps of:

computing, for a second CDN in the CDN list, a second bit rate at which the second CDN can download the portion of the digital content file to the content player machine; and

determining whether the second bit rate is equal to the highest bit rate associated with the content player machine.

16. The computer-readable medium of claim 12, wherein no CDN in the CDN list is capable of downloading the portion of the digital content file to the content player machine at the highest bit rate, and the step of selecting comprises the steps of:

for each CDN included in the CDN list, computing a bit rate at which the portion of the digital content file can be downloaded to the content player machine; and

for each CDN included in the CDN list, computing a weighted bandwidth equal to the product of the bit rate at which the CDN can download the portion of the digital content file to the content player machine and the weight included in the CDN list for the CDN.

17. The computer-readable medium of claim 16, wherein a first CDN in the CDN list has a weighted bandwidth that is greater than the weighted bandwidth associated with any other CDN included in the CDN list, and the step of selecting further comprises the step of selecting the first CDN.

18. The computer-readable medium of claim 16, wherein two or more CDNs in the CDN list have the same weighted bandwidth, and the step of selecting further comprises the step of selecting a first CDN of the two or more CDNs that has the lowest relative rank set forth in the CDN list.

19. The computer-readable medium of claim 12, wherein the buffering thread is further configured to continue downloading and storing the digital content associated with the digital content file until the buffering thread encounters a quit signal indicating that a buffer under-run condition has occurred or an end-of-stream signal indicating that the entire digital content file has been downloaded and played.

20. The computer-readable medium of claim 19, wherein the playback thread is configured to:

continue playing the digital content stored in the content buffer until determining that the content buffer is empty; and

send the quit signal to the buffering thread, if the entire digital content file has not been played, or

send the end-of-stream signal to a content player management thread, if the entire digital content file has been played.

21. A content player device configured to download a digital content file from a content distribution network (CDN) residing within a content distribution system, the content player device comprising:

a memory that includes a content buffer for storing downloaded digital content; and

a processing unit coupled to the memory and configured to;

receive a CDN list from a content directory server that includes one or more CDNs residing within the content distribution system and also includes a rank and a weight for each of the one or more CDNs,

select a CDN from the CDN list from which to download the digital content file based on a bandwidth test, wherein the selected CDN is capable of downloading a portion of the digital content file to the content player device at a highest bit rate associated with the content player device or has a weighted bandwidth greater than or equal to the weighted bandwidth associated with any other CDN included in the CDN list,

launch a buffering thread configured to download digital content associated with the digital content file from the selected CDN and to store the digital content in the content buffer, and

launch a playback thread configured to play the digital content stored in the content buffer on a display device coupled to the content player device.