CONDITIONAL PROTOCOL CONTROL

• US 20100250701A1
• Filed: 10/02/2009
• Published: 09/30/2010
• Est. Priority Date: 03/26/2009
• Status: Active Grant

• Current Assignee: Limelight Networks, Inc.
• Original Assignee: Limelight Networks, Inc.
• Inventors: Wolfe, Jason L., DePalo, Joseph D., Harvell, Bradley B., Gordon, Michael M.
• Granted Patent: US 8,274,909 B2
• Time in Patent Office: Days
• US Class Current: 709/217
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 47/24 Traffic characterised by specific attributes, e.g. priority or QoS
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/29 using a combination of thresholds
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]

Abstract

Techniques for modifying the performance of a transport layer protocol in response to a request for content are disclosed. A connection can be established between a content distribution server and an end user computer according to preconfigured parameters. When a request for content is received over the connection, the content distribution server can determine one or more parameters relating to the performance of the connection using information from the request. The content distribution server can modify the connection at the transport layer according to the one or more parameters. Thereafter, the transport layer can manage delivery of the requested content to the end user computer in accordance with the modified parameters. In various embodiments, the content distribution server includes a modified TCP protocol stack which adjusts timing, pacing, and buffer allocation associated with a connection in response to requests from an application-layer data source.

Claims

1. A method for managing delivery of content in a system comprising a server and an end user computer, comprising:

establishing a first connection at the server for communicating with the end user computer;

receiving a request for content from the end user computer over the first connection;

determining one or more parameters relating to the performance of the first connection using information from the request;

modifying the first connection at the transport layer based on the one or more parameters; and

sending the requested content from the server to the end user computer such that the transport layer manages delivery of the content in accordance with the modified parameters.

2. The method of claim 1, further comprising:

determining a latency characteristic of the first connection; and

modifying the first connection at the transport layer based on the latency characteristic.

3. The method of claim 1, further comprising:

determining a connection type of the end user computer;

determining a latency characteristic associated with the connection type; and

modifying the first connection at the transport layer based on the latency characteristic associated with the connection type of the end user computer.

4. The method of claim 1, further comprising:

determining a data size of the requested content;

measuring a round trip travel time between the server and the end user computer when the data size exceeds a predetermined value; and

modifying the first connection at the transport layer based on the size of the requested content and the round trip travel time.

5. The method of claim 1, further comprising:

determining a geographic region of the end user computer; and

modifying the first connection based on network characteristics of the geographic region.

6. The method of claim 1, further comprising:

determining an autonomous system (AS) from which the first connection is received; and

modifying the first connection based on network characteristics of the autonomous system.

7. The method of claim 1, further comprising:

determining a link utilization between the server and an autonomous system of the end user computer; and

modifying the first connection based on the link utilization.

8. The method of claim 1, further comprising:

retrieving metadata associated with a requested file; and

modifying the first connection based on the metadata.

9. The method of claim 1, further comprising:

determining a predetermined performance profile for the first connection using the information from the request; and

modifying the first connection based on the predetermined performance profile.

10. The method of claim 1, further comprising:

determining whether the requested content is available at the server;

obtaining the requested content from a second server when the requested content is not available at the server; and

caching the requested content at the server for at least a predetermined time.

11. The method of claim 1, wherein modifying the first connection comprises adjusting a timing of data transmission at the transport layer in accordance with the one or more parameters.

12. The method of claim 1, wherein modifying the first connection comprises adjusting a transport layer send window associated with the first connection.

13. The method of claim 1, wherein modifying the first connection comprises adjusting a burst size of the first connection so as to pace data transmission according to the one or more parameters.

14. The method of claim 1, wherein the transport layer protocol is the Transmission Control Protocol (TCP).

15. A content distribution server, comprising:

a network interface having a plurality of ports configured to send and receive data over a connecting network;

a processor coupled to the network interface and configured to manage a plurality of connections to end user computers;

a protocol handler configured to establish the plurality of connections with the end user computers according to predetermined transport layer parameters of the content distribution server and to manage data transmission over the plurality of connections, and

a data source configured to supply requested content to the end user computers over the plurality of connections,

wherein the data source is configured to monitor a first connection for a request, to determine one or more transport layer parameters for the first connection based on the request, and to direct the protocol handler to modify the first connection based on the one or more transport layer parameters independently of other connections of the content distribution server.

16. The content distribution server of claim 15, further comprising:

a protocol attribute information store having information relating data associated with a content request to the one or more connection parameters,

wherein the data source determines the one or more transport layer performance parameters based on information retrieved from the protocol attribute information store.

17. The content distribution server of claim 16, wherein the protocol attribute information store comprises metadata associated with files available from the content distribution server and performance parameters corresponding to the files.

18. The content distribution server of claim 15, wherein the data source determines a geographic region corresponding to a destination address of the first connection, and wherein the one or more transport layer parameters are determined based on the geographic region.

19. The content distribution server of claim 15, wherein the data source determines an autonomous system (AS) associated with the first connection, and wherein the one or more transport layer parameters are determined based on network characteristics of the autonomous system.

20. The content distribution server of claim 15, wherein the data source determines a latency characteristic associated with the first connection based on the information from the request and directs the protocol attribute selector to modify the first connection at the transport layer based on the latency characteristic.

21. The content distribution server of claim 15, wherein the protocol handler is configured to adjust a timing of data transmission at the transport layer based on the one or more performance parameters.

22. The content distribution server of claim 15, wherein the protocol handler is configured to adjust a size of a transport layer send window associated with the first connection.

23. The content distribution server of claim 15, wherein the protocol handler is configured to adjust a burst size of the first connection so as to pace data transmission according to the one or more parameters.

24. A computer program product comprising a computer-readable medium encoded with one or more sequences of one or more instructions which, when executed by a processor, cause a computer to:

establish a first connection for communicating with an end user computer;

receive a request for content from the end user computer over the first connection;

determine one or more parameters relating to the performance of the first connection based on information from the request;

modify the first connection at the transport layer using the one or more parameters; and

send the requested content to the end user computer such that the transport layer manages delivery of the content in accordance with the modified parameters.

25. A content distribution server, comprising:

means for sending and receiving data over a connecting network;

means for managing a plurality of connections to end user computers;

means for establishing a connection with each end user computer according to predetermined transport layer parameters of the content distribution server;

means for managing data transmission over the plurality of connections;

means for modifying a connection based on one or more transport layer performance parameters; and

means for supplying the requested content to the end user computers over the plurality of connections, comprising;

means for monitoring a first connection for a request,

means for determining the one or more transport layer performance parameters for the first connection based on the request, and

means for causing the modifying means to modify the first connection independently of other connections of the content distribution server based on the one or more transport layer performance parameters.