Efficient content server using request redirection

• US 6,553,376 B1
• Filed: 11/16/1999
• Issued: 04/22/2003
• Est. Priority Date: 11/18/1998
• Status: Expired due to Term

• Current Assignee: Array Networks Incorporated (Hitachi, Ltd.)
• Original Assignee: InfoLibria, Inc. (Hitachi, Ltd.)
• Inventors: Hoey, David L., Lewis, Kevin T.
• Primary Examiner(s): Robinson, Greta
• Assistant Examiner(s): Black, Linh
• Application Number:
  US09/440,975
• Time in Patent Office: 1,253 Days
• Field of Search: 707/1-10, 707/100-104, 707/500-542, 709/200-203, 709/217-219, 709/226, 709/227-229
• US Class Current: 1/1
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: H04L 65/1043 Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 67/289 Intermediate processing functionally located close to the data consumer application, e.g. in same machine, in same home or in same sub-network
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing

Abstract

A technique for optimizing delivery of specialized content files such as multimedia files in a computer network. A multimedia file cache is located at a point of presence, such as at an Internet Service Provider (ISP), gateway, or other place close to user connection points into the network. A redirection function intercepts media redirection file requests sent to or from the media server and rewrites such requests so that they point to the local media file cache.

Claims

1. A method of servicing requests for delivery of a media content file in a network of client-server computing systems in which a client computer makes an inquiry to an origin server to locate a media server associated with the origin server which stores the media content file, and wherein a local media cache is located within the network, the method comprising the steps of:

at the client, requesting delivery of the media content file by requesting from the origin server the delivery of a media redirection file (MRF) containing a redirection object specifying instructions for obtaining the media content file from the media server;

prior to delivery of the media redirection file from the origin server to the client, intercepting the media redirection file at a node on the network between the origin server and client;

rewriting instructions contained in the intercepted media redirection file; and

sending the media redirection file including rewritten instructions to the client so that the media content file is obtained from the local media cache by the client instead of from the media server.

2. A method as in claim 1 wherein the step of intercepting the media redirection file is performed at a node in the network near the client.

3. A method as in claim 1 wherein the step of intercepting the media redirection file is performed at an intermediate node in the network.

4. A method as in claim 1 wherein the step of intercepting the media redirection file is performed at the origin server.

5. A method as in claim 1 wherein the step of intercepting the media redirection file is modified at a link layer.

6. A method as in claim 1 wherein the local media cache is selected from among multiple media caches.

7. A method as in claim 1 wherein the media content file is stored in the local media cache prior to the client requesting delivery of the media content file.

8. A method as in claim 1 additionally comprising the step of:

determining an observed link bandwidth for file transfers between the local media cache and the client; and

rewriting the instructions in the media redirection file to specify one of a plurality of media content files depending upon the observed link bandwidth.

9. A method as in claim 6 wherein the multiple media caches are arranged and selected in accordance with a fault tolerance capability.

10. A method as in claim 1 wherein the multiple media caches are arranged as a cache cluster.

12. A method as in claim 1 additionally comprising the step of:

before rewriting the instructions contained in the media redirection file, determining if the media content file is stored at the local cache server.

13. A method as in claim 1 wherein the step of rewriting the instructions further comprises the step of rewriting an <

href>

tag within the media redirection file to insert a Uniform Resource Location (URL) of the media cache.

11. A method of servicing requests for delivery of a media content file in a network of client-server computing systems in which a client computer makes an inquiry to an origin server to locate a media server associated with the origin server which stores the media content file, and wherein a local media cache is located within the network at a point near the client, the method comprising the steps of:

at the client, requesting delivery of the media content file by requesting from the origin server the delivery of a media redirection file (MRU) containing a redirection object specifying instructions for obtaining the media content file from the media server;

prior to delivery of the media redirection file to the client, intercepting the media redirection file and rewriting the instructions contained therein so that the media content file is obtained from the local media cache by the client instead of from the media server directly; and

charging the user of the client computer a premium for intercepting media redirection files.

14. A method of servicing requests for delivery of media content in a network of client-server computing systems, the method comprising the steps of:

transmitting a request from a client to a first server over the network;

in response to receiving the request, generating a file at the first server, the file including information indicating an address for retrieving media content associated with the request from the client;

sending the file over the network for receipt by the client;

prior to receipt of the file by the client, intercepting the file at a node of the network;

modifying the file at the node of the network; and

forwarding the modified file to the client.

15. A method as in claim 14 further comprising:

processing the file at the client to identify an address associated with retrieving the media content; and

retrieving the media content at the client from a different server than originally intended by the first server.

16. A method as in claim 14, wherein the file is a media redirection file (MRF) including a redirection object specifying instructions for obtaining the media content file from a media server.

17. A method as in claim 14, wherein the file generated by the first server indicates a second server from which the client should retrieve media content and the file is modified to indicate a third server from which the client should retrieve the media content.

18. A method as in claim 17, wherein the third server is a local cache server located at an intermediate node between the client and first server.

19. A method as in claim 14, wherein the media content is retrieved from a local cache server located in a vicinity of the node of the network intercepting the file.

20. A method as in claim 14 further comprising:

processing the file at the node of the network to determine whether a local media cache server includes the media content being requested by the client; and

retrieving the media content by the client from the local cache media instead of as originally intended by the first server.

21. A method as in claim 20, wherein the server is a local media cache server disposed nearer the client than the originally intended server.

22. A method as in claim 20, modifying an address in the file so that media content is retrieved from a different server than originally intended by the first server generating the file.

23. A method as in claim 14 further comprising:

determining that a local media cache does not include requested media content; and

from the node intercepting the file, forwarding the file to the client so that the client retrieves the media content from a server as originally intended by the first server.

24. A method of servicing requests for delivery of media content in a network of client-server computing systems, the method comprising the steps of:

at an origin server that generates media redirection files, receiving a request from a client for information related to specific media content;

maintaining at least one media cache connected to the network to satisfy the request for media content, the at least one media cache including a copy of the media content that is optionally provided by an alternate media content server;

selecting one of the at least one media cache to service the client request;

generating a media redirection file to include an address of the selected media cache that will provide data to satisfy the request for media content; and

sending the generated media redirection file to the requesting client.

25. A method as in claim 24, wherein multiple media caches are located at points of presence on the network.

26. A method as in claim 24, wherein the media redirection file is modified based on load balancing for efficient distribution of frequently requested media content.

27. A method as in claim 24 further comprising:

charging a premium for modifying media redirection files.

28. A method as in claim 24 further comprising:

examining the media redirection file;

determining a closest media;

cache in which the requesting client can access; and

modifying the media redirection file to include a reference to the closest media cache that the requesting client can access.

29. A method as in claim 24, wherein the media content requested by the client is streaming data information.

30. A method as in claim 24 further comprising:

identifying a media cache located at a point of presence that can satisfy the request for media content; and

modifying the media redirection file to include a reference address to the media cache located at the point of presence to serve requesting client.

31. A method as in claim 24, wherein the origin server is a Domain Name Server (DNS) that resolves domain names to physical addresses.

32. A method as in claim 24, wherein the client requesting information related to the content media transmits messages across the Internet to communicate with the origin server.

33. A method as in claim 24 further comprising:

examining the media redirection file;

determining a media cache from which the requesting client can access most quickly; and

modifying the media redirection file to include an address to the most quickly accessible media cache.

34. A method as in claim 24, wherein the step of modifying the media redirection file includes modifying an address from which media content will be retrieved.

35. A method as in claim 24 further comprising:

a media redirection file so that the media content is provided by a media cache server that is more easily accessible by the client than the alternate media server.