System and method for data distribution and recovery

• US 6,965,916 B1
• Filed: 12/14/2000
• Issued: 11/15/2005
• Est. Priority Date: 12/14/2000
• Status: Expired due to Fees

• Current Assignee: Bellsouth Intellectual Property Corporation (AT&T, Inc.)
• Original Assignee: Bellsouth Intellectual Property Corporation (AT&T, Inc.)
• Inventors: Kling, Brian D., Fingerhut, Howard W., Kashinsky, Jeffrey D.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): DELGADO, MICHAEL A
• Application Number:
  US09/735,890
• Time in Patent Office: 1,797 Days
• Field of Search: 709/203, 709/217, 709/235, 709/237, 709/205, 370/394, 370/216, 719/328, 713/176, 714/2
• US Class Current: 709/205
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 12/1868 Measures taken after transmission, e.g. acknowledgments
• CPC Class Codes: H04L 67/55 Push-based network services
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99946 Object-oriented database structure network
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A system and method for data distribution and recovery, including a server that broadcasts data to a plurality of clients and a means for a client to identify and recover broadcast data that the client missed while it was off line. In a representative embodiment, the system includes a transfer server, a plurality of clients in communication with the transfer server, and an archive in communication with the transfer server and the plurality of clients. The transfer server receives data packets from a data source, uniquely identifies each data packet, and broadcasts the data packets to the plurality of clients and the archive. Each client receives the data broadcast from the transfer server, identifies missing data, and communicates with the archive to recover the missing data.

Claims

1. A method for data distribution and recovery comprising the steps of:

attaching unique sequence numbers to data packets;

broadcasting the data packets from a server to a plurality of clients and an archive;

waiting, at the server, for an acknowledgement from the archive for each individual data packet of the data packets, wherein the server receives the acknowledgement upon the archive receiving and storing the individual data packet, and wherein if the server does not receive the acknowledgement, then the server stores the individual data packet;

storing the data packets with their attached unique sequence numbers that have been received at the plurality of clients;

monitoring for a missing sequence number at a client;

sending a query from the client that requests re-transmission of a missing data packet having the missing sequence number; and

transmitting to the client the missing data packet

wherein the step of sending a query comprises sending the query from the client to the archive and wherein if the archive does not respond or if the archive does not have the missing data packet then the step of sending a query further comprises sending the query to the server.

2. The method of claim 1, wherein the unique sequence numbers identify the data packets and denote an order in which the data packets are broadcast.

3. The method of claim 2, wherein the unique sequence numbers contain enough digits to ensure that no two data packets receive identical sequence numbers.

4. The method of claim 2, wherein the unique sequence numbers are 32-bit sequence numbers.

5. The method of claim 1, wherein the step of monitoring for a missing sequence number at the client comprises the steps of:

(i) receiving a first data packet and recording a first unique sequence number associated with the first data packet;

(ii) receiving a second data packet and recording a second unique sequence number associated with the second data packet;

(iii) comparing the first unique sequence number to the second unique sequence number; and

(iv) if the second unique sequence number is not in sequence after the first unique sequence number, then determining that the client is missing a sequence number.

6. The method of claim 5, further comprising the step of:

(v) if the second unique sequence number is in sequence after the first unique sequence number, then determining that the client is not missing a sequence number.

7. The method of claim 1, wherein, if the archive has the missing data packet, then the archive transmits the missing data packet to the client.

8. The method of claim 7, wherein the archive transmits the missing data packet to the client in a point-to-point communication.

9. The method of claim 7, wherein the archive transmits the missing data packet to the client in a broadcast communication using subject-based addressing.

10. The method of claim 1, wherein, if the server has the missing data packet, then the server transmits the missing data packet to the client.

11. The method of claim 10, wherein the server transmits the missing data packet to the client in a point-to-point communication.

12. The method of claim 10, wherein the server transmits the missing data packet to the client in a broadcast communication using subject-based addressing.

13. A method for distributing data comprising:

attaching a unique sequence number to each of a sequence of data packets;

transmitting the data packets from a server to a plurality of clients and to an archive;

receiving one or more of the data packets at the archive;

storing the received data packets at the archive;

determining whether a client of the plurality of clients has not received at least one of the data packets; and

upon determining that a data packet has not been received by the client, sending a query from the client to the archive, and wherein, if the archive does not respond or if the archive does not have the missing data packet, then sending a query from the client to the server; and

re-transmitting the data packets that have not been received by the client to the client from the archive in response to the query if the archive has the missing data packet or from the server in response to the query if the archive does not have the missing data packet.

14. The method of claim 13, wherein after the step of receiving the data packets at the archive, the method further comprises sending an acknowledgement for the each of the sequence of data packets that is received.

15. The method of claim 14, wherein the acknowledgement references the unique sequence number for the each of the sequence of data packets that is received.

16. The method of claim 13, wherein the step of determining whether a client of the plurality of clients has not received at least one of the data packets comprises identifying an absence of at least one unique sequence number at the client.

17. The method of claim 13, wherein transmitting the data packets to a plurality of clients and to an archive comprises broadcasting the data packets.

18. The method of claim 13, wherein re-transmitting the data packets that have not been received by the client to the client uses a point-to-point communication.

19. A computer readable medium having instructions that when executed by a server computer, an archive computer, and a plurality of client computers results in acts comprising:

attaching a unique sequence number to each of a sequence of data packets;

transmitting the data packets from the server computer to the plurality of client computers and to the archive computer;

receiving one or more of the data packets at the archive computer;

storing the received data packets at the archive computer;

determining whether a client computer of the plurality of client computers has not received at least one of the data packets;

upon determining that a data packet has not been received by the client computer, sending a query from the client computer to the archive computer, and wherein, if the archive computer does not respond or if the archive computer does not have the missing data packet, then sending a query from the client computer to the server computer; and

re-transmitting the data packets that have not been received by the client computer to the client computer from the archive computer in response to the query if the archive computer has the missing data packet or from the server computer in response to the query if the archive computer does not have the missing data packet.

20. The computer readable medium of claim 19, wherein the acts further comprise, after the act of receiving the one or more data packets at the archive computer, sending an acknowledgement for the each of the sequence of data packets that is received.

21. The computer readable medium of claim 20, wherein the acknowledgement references the unique sequence number for the each of the sequence of data packets that is received.

22. The computer readable medium of claim 19, wherein the act of determining whether a client computer of the plurality of client computers has not received at least one of the data packets comprises identifying an absence of at least one unique sequence number at the client computer.

23. The computer readable medium of claim 19, wherein transmitting the data packets to a plurality of client computers and to an archive computer comprises broadcasting the data packets.

24. The computer readable medium of claim 19, wherein re-transmitting the data packets that have not been received by the client computer to the client computer uses a point-to-point communication.