Methods and apparatus for managing access to data through a network device

• US 7,624,184 B1
• Filed: 06/06/2001
• Issued: 11/24/2009
• Est. Priority Date: 06/06/2001
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Sutton, Carl D., Aviani, James A., Gourlay, Douglas A.
• Primary Examiner(s): BOUTAH, ALINA A
• Application Number:
  US09/875,543
• Time in Patent Office: 3,093 Days
• Field of Search: 709227-229, 709/203, 709/237, 709212-213, 709/216, 709/225, 709/232, 709/239
• US Class Current: 709/227
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data

Abstract

The invention is directed to techniques for managing access to data available from a data access device using a network switching protocol to manage content requests from clients. A data communications device receives a request for content from a client. The data communications device, such as a network switch, exchanges signals using the network switching protocol with one or more data access devices, such as a web cache. The data communications device can then select one data access device to provide the requested content to the client based, for example, on load balancing considerations. The data communications device sends a data transfer approval signal to the selected data access device. The selected data access device establishes a connection with the client using information, such as the client'"'"'s network address, provided by the signals. The selected data access device then bypasses the data communications device and sends the requested content to the client. Using the network switching protocol, the data communications device can manage multiple, pipelined requests from the same client, while approving responses to the client from different data access devices, such as web caches and/or servers.

Claims

1. A method, comprising:

receiving a first request in a data communications device from a client to access data;

providing a second request to access data to a data access device in response to receiving the first request, the second request including a heads up switching protocol which includes additional connection establishment information that enables establishment of a communication connection between the data access device and the client;

receiving a first response from the data access device in the data communications device in response to the second request, the first response including a heads up switching protocol; and

providing a data transfer approval to the data access device in response to receiving the first response, the data transfer approval authorizing the data access device to establish the communication connection to the client by bypassing the data communications device based on the connection establishment information and to provide a second response to the second request to the client by bypassing the data communications device through the communication connection established by the data access device as a result of the data transfer approval.

2. The method of claim 1, where

receiving the first request comprises receiving the first request based on a request/response communications protocol, and receiving a content identifier that identifies a requested content;

and

providing the second request comprises providing the content identifier to enable the data access device to access the requested content.

3. The method of claim 1, where

receiving the first request comprises receiving a plurality of first requests from the client to access data;

providing the second request comprises providing a plurality of second requests in response to receiving the first requests, the second requests including a request sequence number; and

providing the data transfer approval comprises providing data transfer approvals for the second requests in a sequence based on the request sequence numbers for the second requests.

4. The method of claim 1, where

providing the second request comprises providing a plurality of second requests to a plurality of data access devices;

receiving the first response comprises receiving a plurality of first responses from a subset of the plurality of data access devices that received the second requests; and

providing the data transfer approval comprises selecting a data access device from the subset of the plurality of data access devices to provide the second response to the second request and providing the data transfer approval to the data access device.

5. The method of claim 4, where the first response includes usage information for each data access device in the subset that indicates a level of usage for each data access device in the subset;

and

selecting a data access device from the subset of the plurality of data access devices comprises comparing the usage information for all of the data access devices in the subset to determine the data access devices from the subset having a preferable level of usage.

6. The method of claim 1, where the connection establishment information includes a current transmit window for the client that provides a window length for transmitting the second response to the client from the data access device, the window length provided by the client in the first request for use by the data access device when determining a quantity of data to provide in the second response.

7. The method of claim 1, where the data access device is a first data access device, and the connection establishment information includes a location identifier for a second data access device suitable for use if a requested content specified in the first request is unavailable from the first data access device.

8. The method of claim 1, where the connection establishment information is a first set of connection establishment information, and the data transfer approval comprises a second set of connection establishment information, the data transfer approval authorizing the data access device to establish the communication connection to the client based on the first set and the second set of connection establishment information.

9. The method of claim 1, comprising:

receiving a first acknowledgment of the second response in the data communications device over the communication connection; and

sending a second acknowledgment from the communications device to the data access device in response to receiving the first acknowledgment indicating that the data communications device received the first acknowledgment from the client.

10. The method of claim 1, comprising:

receiving in the communications device a first termination signal from the data access device in order to terminate a request session with the client; and

providing a second termination signal to the client in response to receiving the first acknowledgment that indicates a request to terminate the request session.

11. A data communications device, comprising:

a processor;

a memory coupled to the processor; and

a communications interface connected to the processor and the memory;

a first receive logic to receive a first request through the communications interface from a client to access data;

a request logic to provide a second request to access data through the communications interface to a data access device in response to receiving the first request, the second request including a heads up switching protocol which includes additional connection establishment information that enables establishment of a communication connection between the data access device and the client;

a second receive logic to receive a first response through the communications interface from the data access device, the first response including a heads up switching protocol; and

an approval logic to provide a data transfer approval through the communications interface to the data access device in response to receiving the first response, the data transfer approval authorizing the data access device to establish the communication connection to the client based, at least in part, on the connection establishment information and to provide a second response to the second request to the client.

12. The data communications device of claim 11, where

the first receive logic is to receive the first request based on a request/response communications protocol, and

a content identifier that identifies a requested content;

and

where the request logic is to provide the content identifier to enable the data access device to access the requested content.

13. The data communications device of claim 11, where

the first receive logic is to receive a plurality of first requests to access data from the client;

the request logic is to provide a plurality of second requests in response to the first receive logic receiving the first requests, the second requests including a request sequence number; and

the approval logic is to provide data transfer approvals for a plurality of responses to the second requests in a sequence based on the request sequence numbers for the second requests.

14. The data communications device of claim 11, where

the request logic is to provide a plurality of second requests to a plurality of data access devices;

the second receive logic is to receive a plurality of first responses from a subset of the plurality of data access devices that received the second requests; and

the approval logic is to select a data access device from the subset of data access devices to provide the second response to the second request and where the approval logic is to provide the data transfer approval to the data access device selected from the subset of the plurality of data access devices.

15. The data communications device of claim 14, where the first responses comprise usage information for data access devices in the subset that indicates a level of usage for data access devices in the subset;

and

where the approval logic is to compare the usage information for all of the data access devices in the subset to determine the data access devices from the subset having a preferable level of usage.

16. The data communications device of claim 11, where the connection establishment information includes a current transmit window for the client that provides a window length for transmitting the second response to the client from the data access device, the window length provided by the client in the first request for use by the data access device when determining a quantity of data to provide in the second response.

17. The data communications device of claim 11, where the data access device is a first data access device, and the connection establishment information includes a location identifier for a second data access device suitable for use if a requested content specified in the first request is unavailable from the first data access device.

18. The data communications device of claim 11, where the connection establishment information is a first set of connection establishment information, and the data transfer approval includes a second set of connection establishment information, the data transfer approval authorizing the data access device to establish the communication connection to the client based on the first set and the second set of connection establishment information.

19. The data communications device of claim 11, where

acknowledgement logic to receive a first acknowledgment through the communications interface from the client of the second response provided to the client from the data access device over the communication connection;

and

where the acknowledgement logic is to forward second acknowledgment through the communications interface to the data access device in response to receiving the first acknowledgment indicating that the data communications device received the first acknowledgment from the client.

20. The data communications device of claim 11, where

a termination logic is to receive a first termination signal through the communications interface from the data access device in order to terminate a request session with the client;

and

where the termination logic is to provide a second termination signal through the communications interface to the client in response to receiving the first acknowledgment that indicates a request to terminate the request session.

21. The data communications device of claim 13, where a sequence number for the first requests distinguish the first requests amongst each other such that a first one of the first requests has a corresponding assigned unique sequence number with respect to a corresponding assigned sequence number assigned to a first one of the second requests.

22. The data communications device of claim 15, where the plurality of second requests are forwarded to the data access device of the subset of the plurality of data access devices in response to a determination, based on receiving the first responses, indicating which of the data access devices are most able to service the first request.

23. The data communication device of claim 11, where the data communication device is a switch, and

where the approval logic providing the data transfer approval results in the data access device establishing the communication connection with the client to service the first request, the communication connection from the data access device to the client bypassing the data communication device;

and

where the connection establishment information in the second request includes a request for content generated by the client, the data access device receiving the request for content prior to establishing a connection between the data access device and the client based on the connection establishment information.

24. The data communication device of claim 23, where the client generates multiple first requests for corresponding different content, the multiple first requests being forwarded form the client to the data communication device, the data communication device generating respective second requests associated with each of the multiple first requests, the data communication device forwarding the respective second requests to two or more data access devices that are able to establish a respective connection and serve requested data, each of the second requests sent from the data communication device to a respective data access device including a request sequence number distinguishing each of the second requests from each other.