Distributed system and method for prefetching objects

• US 6,598,048 B2
• Filed: 07/12/2001
• Issued: 07/22/2003
• Est. Priority Date: 08/06/1997
• Status: Expired due to Fees

• Current Assignee: Tachyon, Inc. (Tachyon Networks Incorporated)
• Original Assignee: Tachyon, Inc. (Tachyon Networks Incorporated)
• Inventors: Fish, Ram A., Guralnick, Jeremy, Carneal, Bruce L.
• Primary Examiner(s): Vu, Kim
• Assistant Examiner(s): FLEURANTIN, JEAN B
• Application Number:
  US09/903,950
• Publication Number:
  US 20020010761A1
• Time in Patent Office: 740 Days
• Field of Search: 707/1, 707/10, 707/103, 707/104.1, 709/218-219, 709/206-207, 709/229, 709/249, 709/203, 711/138
• US Class Current: 1/1
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: H04B 7/18582 Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/2876 Pairs of inter-processing entities at each side of the network, e.g. split proxies
• 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 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/5681 Pre-fetching or pre-delivering data based on network characteristics
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 707/99931 Database or file accessing

Abstract

A distributed proxy server is provided which reduces a delay associated with the retrieval of inline objects of web pages retrieved over a satellite link. The distributed proxy server includes a first component which runs on the browser side of the satellite link and communicates with web browsers, and a second component which runs on an Internet side of the satellite link and communicates with web servers. When a web page is requested over the satellite link and communicates with web servers. When a web page is requested over the satellite ink, the second component determines whether the parent file includes any references to inline objects, and prefetches each such inline object. The prefetched objects are transmitted over the satellite link to the first component, which in-turn stores the prefetched objets in a cache and provides the prefetched objects to the requesting web browser. The first component may also block browser requests for prefetched inline objects from unnecessarily being transmitted over the satellite link.

Claims

1. A system for reducing a delay associated with the retrieval of embedded objects of web pages retrieved over a satellite link, the system comprising:

a first component which resides on a user side of the satellite link and communicates with a web browser; and

a second component which resides on an Internet side of the satellite link and communicates over the satellite link with the first component;

wherein the first component is responsive to a request from the web browser for a web page by at least passing the request over the satellite link to the second component;

and wherein the second component is responsive to the request by at least;

sending the request over the Internet to a web server, and receiving an HTML file from the web server in response to the request;

sending the HTML file over the satellite link to the first component for delivery to the web browser;

processing coding of the HTML file to determine whether the web page includes an embedded object to be prefetched; and

in response to detection of an embedded object to be prefetched, prefetching the embedded object over the Internet and passing the prefetched object over the satellite link to the first component;

whereby prefetching of the embedded object is initiated on the Internet side of the satellite link without waiting for the HTML file to traverse the satellite link.

2. The system as in claim 1, wherein the first component stores the prefetched object in a cache memory, and responds to a request from the web browser for the object by returning the object from the cache memory.

3. The system as in claim 1, wherein the first component prevents a browser request for a prefetched object from being transmitted over the satellite link.

4. The system as in claim 1, wherein the second component notifies the first component that the object is being prefetched.

5. The system as in claim 4, wherein the second component notifies the first component by generating a list of objects included in the web page, and sending the list over the satellite link to the first component.

6. The system as in claim 1, wherein the second component is responsive to detection of multiple objects in the web page by prefetching each of the multiple objects.

7. The system as in claim 1, wherein the second component determines whether the web page includes an object to be prefetched by scanning the coding of the HTML file for meta tags associated with embedded objects.

8. The system as in claim 1, wherein the first and second components operate transparently to the web browser.

9. The system as in claim 8, wherein the first and second components further operate transparently to the web server.

10. The system as in claim 1, wherein the first component communicates with the web browser using an HTTP protocol.

11. The system as in claim 1, wherein the first component and the web browser run on a common computer.

12. The system as in claim 1, wherein the first and second components provide object prefetching services to a plurality web browsers.

13. The system as in claim 1, wherein the satellite link includes link to a satellite in a geosynchronous orbit.

14. The system as in claim 1, wherein the second component runs on a satellite gateway machine.

15. A method of reducing load times of web pages over a satellite link which provides a connection to a wide area network, the method comprising:

on a user side of the satellite link, receiving a request for a web page from a web browser and forwarding the request over the satellite link to a wide area network side;

on the wide area network side of the satellite link, responding to the request by at least;

(a) forwarding the request over the wide area network to a web server, and receiving an HTML file from the web server in response to the request;

(b) sending the HTML file over the satellite link to the user side for delivery to the web browser;

(c) processing coding of the HTML file to determine whether the web page includes one or more objects to be prefetched; and

(d) in response to detection of an object to be prefetched in (c), prefetching the object over the wide area network and sending the prefetched object over the satellite link to the user side.

16. A The method as in claim 15, further comprising storing the prefetched object in a cache memory on the user side of the satellite link, and responding to a request from the web browser for the object by returning the object from the cache.

17. The method as in claim 15, further comprising blocking a browser request for the object from being transmitted over the satellite link.

18. The method as in claim 15, wherein prefetching of the object in (d) occurs while the HTML file is being transmitted over the satellite link to the user side.

19. The method as in claim 15, further comprising transmitting a message over the satellite link from the wide area network side to the user side indicating that the object is being prefetched.

20. The method as in claim 19, wherein the message indicates that the web page comprises a plurality of objects that are being prefetched.

21. The method as in claim 15, wherein (c) comprises scanning the coding of the HTML file for meta tags of a predetermined type.

22. The method as in claim 15, wherein the object is an inline object.

23. The method as in claim 15, wherein the object is prefetched transparently to the web browser.

24. The method as in claim 23, wherein the object is further prefetched transparently to the web server.

25. The method as in claim 15, wherein the satellite link includes a link to a satellite in a geosynchronous orbit.

26. The method as in claim 15, wherein the request for the web page is an HTTP request generated by a non-prefetch-aware web browser.

27. A method of reducing load times of web pages over a satellite link which couples a web browser to the Internet, the method comprising:

at a node which is located remotely from the web browser and is coupled to the web browser by the satellite link;

receiving from the satellite link a request from the web browser for the web page;

forwarding the request to a web server, and receiving a parent file of the web page from the web server in response to the request;

sending the parent file over the satellite link for delivery to the web browser;

processing the parent file to determine whether the web page includes an object to be prefetched; and

in response to detection of an object to be prefetched, prefetching the object from the web server and passing the prefetched object over the satellite link for delivery to the web browser.

28. The method as in claim 27, wherein the parent file is an HTML file.

29. The method as in claim 28, wherein processing the parent file comprises scanning coding of the HTML file for meta tags of a predetermined type.

30. The method as in claim 27, further comprising storing the prefetched object in a cache memory on a user side of the satellite link, and responding to a request from the web browser for the object by returning the object from the cache.

31. The method as in claim 27, further comprising blocking a browser request for the object from being transmitted over the satellite link.

32. The method as in claim 27, wherein the object is prefetched while the parent file is being transferred over the satellite link.

33. The method as in claim 27, wherein the node additionally sends a message over the satellite link indicating that the object is being prefetched.

34. The method as in claim 33, wherein the message indicates that the web page comprises a plurality of objects that are being prefetched.

35. The method as in claim 27, wherein the object is an inline object.

36. The method as in claim 27, wherein the object is prefetched transparently to the web browser.

37. The method as in claim 36, wherein the object is further prefetched transparently to the web server.

38. The method as in claim 27, wherein the satellite link includes a link to a satellite in geosynchronous orbit.

39. The method as in claim 27, wherein the node retrieves the parent file and the object from the web server over a wide area network.

40. A system for providing Internet access by satellite, comprising:

a wireless satellite link which forms a part of a communications channel between a web browser and a web server; and

a distributed proxy server distributed across the satellite link, said distributed proxy server configured to prefetch inline objects of web pages requested from the web server by the web browser such that prefetching of inline objects is initiated on a side of the satellite link corresponding to the web server, and such that said prefetching occurs transparently to at least the web server.

41. The system as in claim 40, wherein the satellite link includes a link to a satellite in a geosynchronous orbit.

42. The system as in claim 40, wherein the distributed proxy server comprises a first component which runs on a side of the satellite link corresponding to the web browser, and which stores prefetched inline objects in a cache memory.

43. The system as in claim 42, wherein the first component blocks a request from the web browser for an inline object that is being prefetched, to prevent the request from unnecessarily being transmitted over the satellite link.

44. The system as in claim 42, wherein the distributed proxy server further includes a second component which runs on a side of the satellite link corresponding to the web server, and which analyzes a parent file of a web page requested by the browser to determine whether the parent file includes any references to inline objects to be prefetched.

45. The system as in claim 40, wherein the distributed proxy server further prefetches the inline objects transparently to the web browser.

46. A system for a web browser to retrieve web pages over a satellite link from web servers, the system comprising:

a first node that resides on a web server side of the satellite link, remotely from the web browser, wherein the first node is responsive to retrieval of a web page by the web browser by processing a parent file of the web page to identify references to embedded objects, and by prefetching the embedded objects for the web browser; and

a second node that resides on a user side of the satellite link locally to the web browser, and communicates over the satellite link with the first node, wherein the second node stores the embedded objects prefetched by the first node in a memory, and provides the embedded objects from the memory to the web browser in response to requests from the web browser for the embedded objects;

whereby the system enables the embedded objects of the web page to be requested on behalf of the web browser before the parent file of the web page reaches the web browser.

47. The system as in claim 46, wherein the first and second nodes operate transparently to the web browser.

48. The system as in claim 47, wherein the first and second nodes further operate transparently to a web server from which the web page is retrieved.

49. The system as in claim 46, wherein the first and second nodes each operate as a part of a distributed proxy server.

50. The system as in claim 46, wherein the first node resides remotely from a web server from which the web page is retrieved.

51. The system as in claim 46, wherein the first node prefetches embedded objects over the Internet from a plurality of web servers.

52. The system as in claim 46, wherein the first node is a satellite gateway node associated with the satellite link.

53. The system as in claim 46, wherein the second node stores prefetched objects for each of a plurality of web browsers.

54. The system as in claim 46, wherein the second node blocks browser requests for embedded objects prefetched by the first node to prevent such browser requests from unnecessarily being transmitted over the satellite link.

55. The system as in claim 46, wherein the satellite link is a geosynchronous orbit satellite link.