Encapsulating protocol for session persistence and reliability

• US 7,562,146 B2
• Filed: 10/10/2003
• Issued: 07/14/2009
• Est. Priority Date: 10/10/2003
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Stone, David, Pedersen, Bradley J., Panasyuk, Anatoliy, Treder, Terry
• Primary Examiner(s): Chang; Jungwon
• Application Number:
  US10/683,881
• Publication Number:
  US 20050080907A1
• Time in Patent Office: 2,104 Days
• Field of Search: 709/227, 709/230, 709/239, 455/439, 370/466, 703/24, 726/15
• US Class Current: 709/227
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 63/0272 Virtual private networks
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0807 using tickets, e.g. Kerberos cryptographic mechanisms or cryptographic arrangements for entity authentication using tickets or tokens H04L9/3213

Abstract

The invention relates to network communications. A first protocol that encapsulates a plurality of secondary protocols is used to communicate over a network. Use of the first protocol provides session persistence and a reliable connection between a client and a host service.

Claims

1. A method for providing a client with a reliable connection to a host service, the method comprising:

establishing, by an agent of a client, stored in memory, a first connection between the client and a first protocol service, stored in memory, using a first protocol communicated over a transport layer protocol, the first protocol being an application level tunneling protocol for encapsulating a plurality of secondary protocols, the agent configured to encapsulate a second protocol within the first protocol and communicate to a host service, stored in memory, using the second protocol;

establishing a second connection between the first protocol service and the host service using one of the plurality of the secondary protocols;

maintaining a queue of data packets most recently transmitted via the first connection on at least one of the client and the first protocol service; and

upon failure of the first connection;

maintaining the second connection;

continuing to maintain the queue of data packets most recently transmitted via the first connection; and

establishing a third connection between the client and the first protocol service using the first protocol.

2. The method of claim 1 further comprising transmitting at least one of the queued data packets via the third connection.

3. The method of claim 1 further comprising closing, by the client or the host service, a first session established with the second protocol.

4. The method of claim 1 further comprising maintaining, by the first protocol service, the first connection with the client established with the first protocol.

5. The method of claim 1, wherein the agent comprises one of an Independent Computing Architecture (ICA) client or a Remote Desktop Protocol (RDP) client.

6. The method of claim 1 wherein the first connection between the client and the first protocol service is established via an intermediary node.

7. The method of claim 1 further comprising compressing communications at a level of the first protocol.

8. The method of claim 1 further comprising encrypting communications at the level of the first protocol.

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

10. The method of claim 1 wherein the second protocol comprises one of:

Hyper Text Transfer Protocol (HTTP), Remote Desktop Protocol (RDP), Independent Computing Architecture (ICA), File Transfer Protocol (FTP), Oscar and Telnet.

11. The method of claim 1 comprising the steps of:

closing connections established with the second protocol; and

maintaining the first connection established with the first protocol.

12. The method of claim 1 wherein the first connection is secure and comprising the steps of:

establishing a second connection between the first protocol service and the host service;

communicating between the client and the host service via the first connection and the second connection;

interrupting the second connection;

establishing a third connection between the first protocol service and a second host service without interrupting the first connection; and

communicating between the client and the second host service via the first connection and the third connection.

13. A system for providing a client with a reliable connection to a host service, the system comprising:

a first protocol service, stored in memory, configured to establish a first connection with the client using a first protocol communicated over a transport layer protocol, the first protocol being an application level tunneling protocol for encapsulating a plurality of secondary protocols, establish a second connection with the host service, stored in memory, using a second protocol, and, upon failure of the first connection, maintain the second connection and accept a third connection from the client;

an agent of a client, stored in memory and configured to encapsulate the second protocol within the first protocol and to communicate to the host service using the second protocol;

the host service configured to accept the second connection with the first protocol service and, upon failure of the first connection;

maintain the second connection,

wherein the first connection and the third connection are each established using a first protocol, the first protocol for encapsulating the plurality of secondary protocols, and wherein at least one of the client and the first protocol service is further configured to maintain, before and upon failure of the first connection;

a queue of data packets most recently transmitted via the first connection.

14. The system of claim 13 wherein the client is further configured to transmit at least one of the queued data packets via the third connection.

15. The system of claim 13 wherein the first protocol service is further configured to transmit at least one of the queued data packets via the third connection.

16. The system of claim 13 wherein the agent comprises one of an Independent Computing Architecture (ICA) client or Remote Desktop Protocol (RDP) client.

17. The system of claim 13 wherein the first connection between the client agent and the first protocol service is established via an intermediary node.

18. The system of claim 13 wherein the client agent compresses communications at a level of the first protocol.

19. The system of claim 13 wherein the client agent encrypts communications at the level of the first protocol.

20. The system of claim 13 wherein the first protocol is Transport Control Protocol (TCP).

21. The system of claim 13 wherein the second protocol comprises one of the following:

Hyper Text Transfer Protocol (HTTP), Remote Desktop Protocol (RDP), Independent Computing Architecture (ICA), File Transfer Protocol (FTP), Oscar and Telnet.

22. The system of claim 13 wherein the connection established with the second protocol is closed and the connection established with the first protocol is maintained.

23. The system of claim 13 further comprising a second host service communicating with the client via the first connection and a third connection, the third connection established between the first protocol service and the second host service without interrupting the first connection and interrupting the second connection, the second connection established between the first protocol service and the host service and the client communicating with the host service via the first connection and the second connection.