Satellite multicast performance enhancing multicast HTTP proxy system and method

• US 6,658,463 B1
• Filed: 02/04/2000
• Issued: 12/02/2003
• Est. Priority Date: 06/10/1999
• Status: Expired due to Term

• Current Assignee: Hughes Network Systems LLC (Echostar Corporation)
• Original Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Inventors: Gaske, T. Paul, Dillon, Douglas M.
• Primary Examiner(s): Wiley, David
• Assistant Examiner(s): Avellino, Joseph E.
• Application Number:
  US09/498,936
• Time in Patent Office: 1,397 Days
• Field of Search: 709/217, 709/219, 709/202, 709/203, 709/204, 707/1, 707/8, 707/100, 707/200, 707/201
• US Class Current: 709/219
• CPC Class Codes: H04L 61/4552 Lookup mechanisms between a plurality of directories; Synchronisation of directories, e.g. metadirectories
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/288 Distributed intermediate devices, i.e. intermediate devices for interaction with other intermediate devices on the same level
• CPC Class Codes: H04L 67/5651 Reducing the amount or size of exchanged application data
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A communication system including an upstream proxy server and two reporting downstream proxy servers, where the upstream proxy server is capable of multicasting a uniform resource locator (URL) to the reporting downstream proxy servers, the reporting downstream proxy servers interact with the upstream proxy server to resolve cache misses and the upstream proxy servers returns a resolution to a cache miss via multicast. A downstream proxy server which filters multicast transmissions of URLs and stores a subset of the URLs for subsequent transmission, where relative popularity is used to determine whether to store a multicast URL. An upstream proxy server capable of multicasting URLs to reporting downstream proxy servers, where the upstream proxy server interacts with the two reporting downstream proxy servers to resolve cache misses and the upstream proxy server returns a resolution to the cache misses via multicast. A proxy server protocol which includes a transaction request further including a request header, request content, and a request extension that supports multicast hit reporting and a transaction response further including a response header, response content, and a response extension which supports multicast cache pre-loading. A transaction response header which includes a popularity field indicating the popularity of a global name with respect to other global names and an expiration field indicating an expiration of the global name.

Claims

1. A communications system comprising:

at least one upstream proxy server; and

at least two reporting downstream proxy servers;

said at least one upstream proxy server capable of multicasting URLs to said at least two reporting downstream proxy servers;

said at least two reporting downstream proxy servers interacting with said at least one upstream proxy server to resolve cache misses;

wherein said at least one upstream proxy server returns at least one resolution to the cache misses via multicast,

where said at least two reporting downstream proxy servers utilize a relative frequency that a source web server of a multicast URL has had items requested by clients of at least one of said at least two reporting downstream proxy servers to determine whether to store a multicast URL.

2. The communication system of claim 1, where said at least one upstream proxy server returns at least one response to the cache misses via point-to-point transmission.

3. The communication system of claim 2, where said at least two reporting downstream proxy servers send cache hit information to said at least one upstream proxy server.

4. The communication system of claim 3, where said at least two reporting downstream proxy servers piggyback cache hit information on HTTP request headers being sent to said at least one upstream proxy server.

5. The communication system of claim 4, where said at least one upstream proxy server uses relative frequency accesses of the URL including both cache misses and cache hits as reported to the upstream server to help determine whether content of a cache miss is returned via multicast or point-to-point transmission.

6. The communication system of claim 2, where said at least one upstream proxy server uses popularity, where popularity is based on a relative frequency of access of a URL, to determine whether the URL is returned via multicast or point-to-point transmission.

7. The communication system of claim 5, where said at least one upstream proxy server also uses a loading of the multicast channel in combination with the popularity to determine whether the URL is returned via multicast or point-to-point transmission.

8. The communication system of claim 2, where said at least one upstream proxy server maps a domain name of a source of a URL to a multicast address to determine the multicast address to be used to carry the URL.

9. The communication system of claim 8, wherein said at least one upstream proxy server maps domain names to multicast addresses using of a hash function.

10. The communication system of claim 8, wherein URLs with a relatively high popularity are carried on a multicast address dedicated to carrying URLs of general interest.

11. The communication system of claim 1, wherein additional reporting downstream proxy servers which are not currently interacting with said at least one upstream proxy server filter multicast cache resolutions from said at least one upstream proxy server and store a subset of cacheable items for subsequent retrievals upon request, by a client.

12. The communication system of claim 1, wherein additional non-reporting downstream proxy servers which do not report to said at least one upstream proxy server filter multicast cache resolutions from said at least one upstream proxy server and store a subset of cacheable items for subsequent retrieval, upon request, by a client.

13. A communication system comprising:

at least one multicast capable upstream proxy server; and

at least two best-effort downstream proxy servers;

said at least one multicast capable upstream proxy server capable of multicasting URLs to said at least two best-effort downstream proxy servers where said at least two best-effort downstream proxy servers interact with said at least one upstream proxy server and either a web-server directly or at least one non-multicast capable proxy server to resolve cache misses;

wherein said at least one multicast capable upstream proxy server returns at least one resolution to the cache misses via multicast; and

wherein said at least two best-effort downstream proxy servers relay responses from said at least one multicast capable proxy server to a client when the responses arrive prior to a response from the web server or said at least one non-multicast capable upstream proxy server.

14. The communication system of claim 13, where said at least two best-effort downstream proxy servers use a best-effort communication mechanism to send cache miss resolution requests to said at least one multicast capable upstream proxy server.

15. The communication system of claim 13, where said at least two best-effort downstream proxy servers send cache hit information to said at least one multicast capable upstream proxy server.

16. The communication system of claim 15, where said at least two best-effort downstream proxy servers piggyback cache hit information on HTTP request headers sent to said at least one multicast capable upstream proxy server.

17. An upstream proxy server capable of multicasting URLs to at least two reporting downstream proxy servers;

said upstream proxy server interacting with said at least two reporting downstream proxy servers to resolve cache misses;

wherein said upstream proxy server returns at least one resolution to the cache misses via multicast,

where said at least one upstream proxy server returns at least one response to the cache misses via point-to-point transmission,

where the upstream proxy server is able to receive cache hit information from at least one downstream proxy server,

where the upstream proxy server uses a relative frequency of cache misses and cache hits to an individual server to determine whether content of a cache miss is returned via multicast or point-to-point transmission.

18. The upstream proxy server of claim 17, where the upstream proxy server is able to receive cache hit information from at least one downstream proxy server piggybacked on an HTTP request from said downstream proxy server.

19. The upstream proxy server of claim 17, where the upstream proxy server uses popularity, where popularity is based on a relative frequency of access of a URL, to determine whether the URL is returned via multicast or point-to-point transmission.

20. The upstream proxy server of claim 19, where the upstream proxy server also uses a loading of the multicast channel in combination with the popularity to determine whether the URL is returned via multicast or point-to-point transmission.