Method and System for Reliable Multicast Data Transmission

• US 20080052590A1
• Filed: 10/29/2007
• Published: 02/28/2008
• Est. Priority Date: 07/17/2003
• Status: Active Grant

• Current Assignee: Micro Focus Software, Inc. (Open Text Corporation)
• Original Assignee: Novell Incorporated (Open Text Corporation)
• Inventors: AMLEKAR, Shekhar
• Granted Patent: US 8,140,927 B2
• Time in Patent Office: Days
• US Class Current: 714/748
• CPC Class Codes: H04L 12/1868 Measures taken after transmission, e.g. acknowledgments
• CPC Class Codes: H04L 45/34 Source routing
• CPC Class Codes: H04L 45/44 Distributed routing

Abstract

Provided is a method and system for reliably multicasting a data transmission from a server to one or more clients, which may be connected via a control channel and a multicast data channel. In one example, the method includes sending a first data transmission to the clients over the multicast data channel. A response is received over the control channel from at least some of the clients. The response identifies data not received by the responding client. In some examples, the response may indicate that all the data was received. The server determines a minimum retransmission data set based on the responses. The minimum retransmission data set includes at least some of the data not received by the client during the first data transmission. The minimum retransmission data set is sent over the multicast data channel and received by the clients that did not receive it during the first data transmission.

Claims

1. A method for receiving multicast data, the method comprising:

receiving at a computer a multicast data transmission over a multicast data channel;

sending from the computer a response over a control channel identifying data not received by the computer during the multicast data transmission; and

receiving at the computer a retransmission, wherein the retransmission includes at least a portion of the data not received by the computer during the multicast data transmission.

2. The method of claim 1 further comprising:

receiving metadata about either the multicast data transmission or the retransmission.

3. The method of claim 2, wherein the metadata includes at least one identifier corresponding to a byte range to be transmitted.

4. The method of claim 2, wherein the metadata includes an IP address corresponding to a computer acting as a server.

5. The method of claim 1, wherein the multicast data transmission is associated with a first IP address, wherein the retransmission is associated with a second IP address, and wherein the first and second addresses are different.

6. The method of claim 1, wherein the computer also acts as a server, wherein acting as a server includes sending from the computer a secondary data transmission.

7. The method of claim 6 wherein the secondary data transmission includes a byte range previously received by the computer.

8. The method of claim 6, wherein the secondary data transmission is sent over the multicast data channel.

9. A method for sending multicast data, the method comprising:

sending a multicast data transmission over a multicast data channel;

receiving a response over a control channel identifying a subset of the data sent during the multicast data transmission; and

sending a retransmission, wherein the retransmission includes at least a portion of the data identified in the response.

10. The method of claim 9 further comprising:

sending metadata about one of the multicast data transmission and the retransmission.

11. The method of claim 10, wherein the metadata includes at least one identifier corresponding to a byte range to be transmitted.

12. The method of claim 10, wherein the metadata includes an IP address corresponding to a computer acting as a server.

13. The method of claim 10, wherein the metadata is sent from a first computer and wherein at least one of the multicast data transmission and the retransmission is sent from a second computer.

14. The method of claim 9 wherein the multicast data transmission is sent from a first computer, and wherein the retransmission is sent from a second computer.

15. A method for receiving multicast data, the method comprising:

receiving at a computer a first data transmission, the first data transmission including a plurality of byte ranges;

identifying a byte range not received during the first data transmission;

sending over a control channel a request for the identified byte range; and

receiving at the computer a second data transmission, wherein the second data transmission includes the identified byte range;

wherein one of the first and second data transmissions is received over a multicast data channel.

16. The method of claim 15 further comprising:

receiving at the computer metadata about either the first or second data transmission.

17. The method of claim 16, wherein the metadata includes at least one identifier corresponding to a byte range.

18. The method of claim 16, wherein the metadata includes an IP address corresponding to a second computer.

19. The method of claim 15, wherein the first data transmission is associated with a first IP address, and wherein the second data transmission is associated with a second IP address.

20. The method of claim 15, wherein the computer also acts as a server, wherein acting as a server includes sending from the computer a third data transmission.

21. The method of claim 20, wherein the third data transmission includes a byte range previously received by the computer.

22. The method of claim 20, wherein the third data transmission is sent over the multicast data channel.