Anycast Aware Transport for Content Distribution Networks

• US 20110055316A1
• Filed: 09/03/2009
• Published: 03/03/2011
• Est. Priority Date: 09/03/2009
• Status: Active Grant

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Rabinovich, Michael Boris, Al-Qudah, Zakaria, Spatscheck, Oliver, Van der Merwe, Jacobus, Lee, Seungjoon
• Granted Patent: US 9,450,804 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1021 based on client or server locations
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 67/5681 Pre-fetching or pre-delivering data based on network characteristics

Abstract

A system for providing content includes a plurality of content delivery servers and a routing control module. Each of the content delivery servers is configured to receive a first request from a client system sent to an anycast IP address for the content, and to provide a first portion of the content to the client system. Each of the content delivery servers is further configured to receive a second request from the client system sent to the anycast IP address for a second portion of the content, and to provide the second portion of the content to the client system. The routing control module is configured to modify the routing of the anycast address from a first content delivery server to a second content delivery server.

Claims

1. A system for providing content, comprising:

first and second content delivery servers, each of the content delivery servers configured to;

receive a first request from a client system sent to an anycast Internet Protocol (IP) address for the content;

provide a first portion of the content to the client system;

receive a second request from the client system sent to the anycast IP address for a second portion of the content; and

provide the second portion of the content to the client system; and

a routing control module configured to modify routing of the anycast address from the first content delivery server to the second content delivery server.

2. The system of claim 1, wherein the second request includes a range request for the second portion of the content.

3. The system of claim 1, wherein the first request is received at the first content delivery server and the second request is received at the second content delivery server.

4. The system of claim 1, wherein each of the content delivery servers is further configured to detect a connection error and to send a connection reset message to the client system in response to the connection error.

5. The system of claim 4, wherein detecting a connection error includes failing to receive a conformation in response to sending a content packet.

6. The system of claim 4, wherein detecting a connection error further includes resending the content packet not greater than once.

7. The system of claim 1, wherein each of the content delivery servers is configured to utilize a higher initial congestion window during a slow-state phase when providing the second portion of the content.

8. A system for providing content, comprising:

a first content delivery server configured to;

receive a request from a client system sent to an anycast Internet Protocol (IP) address for the content;

establish a connection to the client system;

provide a first portion of the content through the connection to the client system;

identify a connection error; and

terminate the connection to the client system in response to identifying the connection error; and

a second content delivery server configured to;

receive a second request from the client system sent to the anycast IP address for a second portion of the content; and

provide the second portion of the content.

9. The system of claim 8, wherein identifying a connection error includes failing to receive a conformation in response to sending a content packet.

10. The system of claim 9, wherein identifying a connection error further includes resending the content packet not more than once.

11. The system of claim 8, wherein terminating the connection includes sending a connection reset message to the client system.

12. The system of claim 8, wherein the second request includes a range request for the second portion of the content.

13. The system of claim 8, wherein the connection error is a result of a routing change.

14. The system of claim 8, wherein the second content delivery server is further configured to skip a slow-start phase when providing the second portion of the content.

15. A computer readable medium comprising a plurality of instructions to manipulate a processor, the plurality of instructions comprising:

instructions to send a request for content to a first server at an anycast Internet Protocol (IP) address;

instructions to receive a first portion of the content from the first server;

instructions to determine that a connection error has occurred;

instructions to send a second request for a second portion of the content to a second server at the anycast IP address in response to the connection error; and

instructions to receive the second portion of the content from the second server.

16. The computer readable medium of claim 15, wherein the second request includes a range request for the second portion of the content.

17. The computer readable medium of claim 15, wherein determining that a connection error has occurred includes receiving a connection reset message.

18. The computer readable medium of claim 15, wherein determining that a connection error has occurred includes not receiving content for a predetermined period of time.

19. The computer readable medium of claim 15, wherein the connection error is a result of a routing change.

20. The computer readable medium of claim 15, further comprising instructions to terminate a download if the connection error occurs during initiating a connection.