Methods and apparatus for streaming media multicast

• US 7,657,644 B1
• Filed: 05/10/2002
• Issued: 02/02/2010
• Est. Priority Date: 05/10/2002
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Zheng, Qinghua
• Primary Examiner(s): Caldwell; Andrew
• Assistant Examiner(s): FORD, GRANT M
• Application Number:
  US10/144,454
• Time in Patent Office: 2,825 Days
• Field of Search: 709217-219, 709/226, 709/246, 709/231, 709/249, 455/503, 395/200.61, 711/118, 370/248
• US Class Current: 709/231
• CPC Class Codes: H04L 12/1827 Network arrangements for conference optimisation or adaptation
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 65/613 for the control of the source by the destination control signals issued by the client directed to the server or network components specially adapted for selective content distribution H04N21/637
• CPC Class Codes: H04L 65/762 at the source reformatting of additional data in video distribution servers H04N21/2355
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A method for a cache for providing streaming media data to a client system includes receiving a request from a client system for a media meta file, the media meta file comprising a unicast URL for a stream of media data, retrieving the media meta file, initiating a connection with a media server associated with the unicast URL, selecting a multicast channel for broadcast of the stream of media data, modifying the media meta file to include data associated with the multicast channel to form a modified media meta file, sending the modified media meta file to the client system, receiving the stream of media data from the media server, and providing the stream of media data on the multicast channel. The client system receives the stream of media data on the multicast channel.

Claims

1. A method for providing streaming media data to a client system comprising:

receiving at a streaming media cache a request from a first client system for a media meta file associated with a stream of Microsoft Media Streaming (MMS) media data, the media meta file having information identifying the stream of media data including a unicast uniform resource locator (URL) for the stream of media data, the request being a request for a unicast connection to the stream of media data;

modifying the media meta file to replace the unicast URL of the media meta file with an IP multicast channel including a multicast IP address, a port number, and an indicator for a Windows Media stream format for the stream of media data;

sending the modified media meta file to the first client system in response to the request, the modified media meta file indicating the multicast channel for the stream of media data in place of the unicast URL for the media meta file;

determining whether the stream of media data is cached at the streaming media cache;

accessing the cached stream of media data if the stream of media data is cached at the streaming media cache;

otherwise,

accessing the stream of media data from a media server with the unicast URL; and

providing the stream of media data on the multicast channel to provide access to the stream of media data to the first client system.

2. The method of claim 1, wherein the modified media meta file indicating the multicast channel comprises the modified media meta file having a specification of a multicast station file that specifies the multicast channel.

3. The method of claim 1, further comprising retrieving the media meta file from a media server that serves the stream of media data, and modifying the retrieved media meta file into the modified media meta file.

4. The method of claim 1, further comprising receiving a request from a second client system for the media meta file, and sending the modified media meta file to the second client system.

5. The method of claim 1, further comprising determining whether one or more clients are active on the multicast channel, and terminating the stream of media data on the multicast channel if no clients are determined to be active on the multicast channel.

6. The method of claim 1, further comprising caching the stream of media data, if the stream of media data is not already cached in the streaming media cache.

7. The method of claim 2, wherein the multicast station file further specifies the unicast URL.

8. The method of claim 4, wherein the request from the second client system comprises a unicast request for the media meta file associated with the stream of media data.

9. The method of claim 5, wherein providing the stream of media data on the multicast channel further comprises receiving the stream of media data on a unicast connection from a media server, and further comprising terminating the unicast connection from the media server if no clients are determined to be active on the multicast channel.

10. An article of manufacture comprising a computer-readable medium having code stored thereon to provide instructions to cause a network device to perform operations including:

receiving a request at a streaming media cache from a first client system for a media meta file associated with a stream of Microsoft Media Streaming (MMS) media data, the media meta file having information identifying the stream of media data including a unicast address for the stream of media data, the request being a request for a unicast connection to the stream of media data;

modifying the media meta file to replace the unicast address of the media meta file with an IP multicast channel indication for the stream of media data to generate a modified media meta file, the multicast channel indication including a multicast IP address, a port number, and an indicator for a Windows Media stream format for the stream of media data;

sending the modified media meta file to the first client system in response to the request for the unicast connection;

determining whether the stream of media data is cached at the streaming media cache;

accessing the cached stream of media data if the stream of media data is cached at the streaming media cache;

otherwise,

accessing the stream of media data from a media server with the unicast URL; and

providing the stream of media data on the multicast channel to provide access to the stream of media data to the first client system.

11. The article of manufacture of claim 10, wherein the modified media meta file indicating the multicast channel comprises a media meta file compatible with one selected from the group consisting of a Windows media meta file and a Real media meta file.

12. The article of manufacture of claim 10, wherein the modified media meta file includes a specification of a multicast station file that specifies the multicast channel and the unicast address.

13. The article of manufacture of claim 10, wherein the multicast channel comprises an Internet Protocol (IP) address and the unicast address comprises a uniform resource locator (URL).

14. The article of manufacture of claim 10, further comprising receiving a request from a second client system for the media meta file, and sending the modified media meta file to the second client system.

15. The article of manufacture of claim 10, further comprising generating an Internet Group Management Protocol (IGMP) query, and sending the IGMP query to the first client system.

16. The article of manufacture of claim 10, further comprising identifying errors in the stream of media data, generating error correcting codes in response to identifying the errors, and sending the error correcting codes to the first client system.

17. The article of manufacture of claim 14, wherein the request from the second client system comprises a request for the multicast station file.

18. A method for receiving streaming media at a client system comprising:

sending a request to a web server for a media meta file associated with a stream of Microsoft Media Streaming (MMS) media data, the media meta file having information identifying the stream of media data including a unicast uniform resource locator (URL) for the stream of media data, the request for a unicast connection to the stream of media data from a media server;

receiving a modified media meta file from a media cache in response to the request, the modified media meta file indicating a multicast channel for the stream of media data in place of the unicast URL for the media meta file, the multicast channel of the modified media meta file being an IP multicast channel including a multicast IP address, a port number, and an indicator for a Windows Media stream format for the stream of media data, where the media cache provides access to a cached copy of the stream of media data if the media cache has cached the stream of media data, otherwise, the media cache accesses the stream of media data from the media server and provides access to the stream of media data; and

accessing the stream of media data on the multicast channel.

19. The method of claim 18, wherein the modified media meta file includes the specification address of the multicast address, a port, a stream format, and the unicast URL.

20. The method of claim 18, further comprising receiving an error correcting code from the media cache.