Anycast transport protocol for content distribution networks

• US 8,560,597 B2
• Filed: 10/16/2009
• Issued: 10/15/2013
• Est. Priority Date: 07/30/2009
• Status: Expired due to Fees

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Spatscheck, Oliver, Lee, Seungjoon, Rabinovich, Michael, Van der Merwe, Jacobus
• Primary Examiner(s): Armouche, Hadi
• Assistant Examiner(s): Harris, Christopher C
• Application Number:
  US12/580,861
• Publication Number:
  US 20110029596A1
• Time in Patent Office: 1,460 Days
• Field of Search: 709/203, 709/231, 709/236, 709/244
• US Class Current: 709/203
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A cache server for providing content includes a processor configured to receive a first datagram from a client system sent to an anycast address, send a response datagram to the client system in response to the first datagram, receive a request datagram from the client system sent to the anycast address, and send a batch of content datagrams to the client system. The first datagram includes a universal resource locator corresponding to the content. The response datagram includes a content identifier for the content. The request datagram includes the content identifier, an offset, and a bandwidth indicator. The batch of content datagrams includes a portion of the content starting at the offset.

Claims

1. A cache server for providing content, comprising:

a hardware processor; and

a memory coupled to the hardware processor, the memory comprising instructions that, when executed by the hardware processor, cause the hardware processor to perform operations comprising;

receiving a first datagram from a client system sent to an anycast internet protocol address, the first datagram including a universal resource locator corresponding to the content;

sending a response datagram to the client system in response to the first datagram, the response datagram including a content identifier for the content;

receiving a first request datagram from the client system sent to the anycast internet protocol address, the first request datagram including the content identifier, an offset, and a first bandwidth indicator;

sending a batch of content datagrams to the client system, the batch of content datagrams including a portion of the content starting at the offset; and

receiving a second request datagram from the client system sent to the anycast internet protocol address, the second request datagram including the content identifier, a new offset, and a second bandwidth indicator, the new offset indicating a beginning of a next portion of the content that begins after the batch of content datagrams sent to the client system, wherein the beginning of the next portion is a number of a next byte of the content, wherein the second bandwidth indicator is based on a recent bandwidth for the portion of the content from the batch of content datagrams and based on a timeout occurring.

2. The server of claim 1, wherein each of the first datagram, the response datagram, the first request datagram, the batch of content datagrams, and the second request datagram is sent using a connectionless protocol.

3. The server of claim 2, wherein the connectionless protocol includes user datagram protocol.

4. The server of claim 1, wherein the batch of content datagrams includes bandwidth verification data.

5. The server of claim 4, wherein the first bandwidth indicator includes the bandwidth verification data and a hash thereof for a previous batch of content datagrams.

6. The server of claim 5, wherein the operations further comprise comparing the first bandwidth indicator to the bandwidth verification data of the previous batch of content datagrams.

7. The server of claim 1, wherein the batch of content datagrams is limited to a maximum number of content datagrams per batch.

8. The server of claim 1, wherein the operations further comprise sending the batch of content datagrams to the client system at a rate not greater than indicated by the first bandwidth indicator.

9. A system for providing content, comprising:

first and second hardware cache servers, each of the cache servers including a storage medium having instructions that, when executed by a processor, cause the processor to perform operations comprising;

receiving a first datagram from a client system sent to an anycast internet protocol address, the first datagram including a universal resource locator corresponding to the content;

sending a response datagram to the client system in response to the first datagram, the response datagram including a content identifier for the content;

receiving a first request datagram from the client system sent to the anycast internet protocol address, the first request datagram including the content identifier, an offset, and a first bandwidth indicator;

verifying, based on the content identifier, that the first request datagram was sent by the client system;

sending, in response to verifying that the first request datagram was sent by the client system, a batch of content datagrams to the client system, the batch of content datagrams including a portion of the content starting at the offset; and

receiving a second request datagram from the client system sent to the anycast internet protocol address, the second request datagram including the content identifier, a new offset, and a second bandwidth indicator, the new offset indicating a next portion of the content that begins after the batch of content datagrams sent to the client system, wherein the second bandwidth indicator is based on a recent bandwidth for the portion of the content from the batch of content datagrams and based on a timeout occurring; and

a routing control module that modifies the routing of the anycast address from the first cache server to the second cache server.

10. The system of claim 9, wherein each of the first datagram, the response datagram, the first request datagram, the batch of content datagrams, and the second request datagram is sent using a connectionless protocol.

11. The system of claim 9, wherein the operations further comprise sending the batch of content datagrams to the client system at a rate not greater than indicated by the first bandwidth indicator.

12. The system of claim 9, wherein the batch of content datagrams includes bandwidth verification data.

13. The system of claim 9, wherein the batch of content datagrams is limited to a maximum number of content datagrams per batch.

14. The system of claim 13, wherein the maximum number of content datagrams per batch is dynamically determined.

15. The system of claim 13, wherein the content datagrams indicate the maximum number of content datagrams per batch.

16. A computer readable device comprising a plurality of instructions, which when executed by a processor of a client system, cause the processor to perform operations comprising:

sending a first datagram to an anycast internet protocol address, the datagram including a universal resource locator corresponding to content;

receiving a content identifier in response to the first datagram, wherein the content identifier includes an address of the client system;

sending a first request datagram to an anycast internet protocol address, the first request datagram including the content identifier, an offset, and a first bandwidth indicator;

receiving a batch of datagrams from a cache server in response to the first request datagram, the batch of datagrams including a portion of the content specified by the content identifier and the offset; and

sending a second request datagram to the anycast internet protocol address, the second request datagram including the content identifier, a new offset, and a second bandwidth indicator, the new offset indicating a next portion of the content that begins after the received batch of content datagrams, wherein the second bandwidth indicator is based on a recent bandwidth for the portion of the content from the batch of content datagrams and based on a timeout occurring.

17. The computer readable device of claim 16, wherein the batch of datagrams include bandwidth verification data.

18. The computer readable device of claim 17, wherein the first bandwidth indicator includes the bandwidth verification data and a hash thereof.

19. The computer readable device of claim 16, wherein the content identifier identifies the content and the client system.

20. The computer readable device of claim 16, wherein the first datagram, the response datagram, the first request datagram, the batch of content datagrams, and the second request datagram are sent using a connectionless protocol.