TRANSMISSION APPARATUS FOR VPN OPTIMIZATION BY DEFRAGMENTATION AND DEDUPLICATION AND METHOD

• US 20110249683A1
• Filed: 06/23/2011
• Published: 10/13/2011
• Est. Priority Date: 04/10/2009
• Status: Active Grant

• Current Assignee: Barracuda Networks Incorporated
• Original Assignee: Barracuda Networks Incorporated
• Inventors: ONGOLE, SUBRAHMANYAM, SRINIVASAN, SRIDHAR
• Granted Patent: US 8,559,450 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 63/0876 based on the identity of the terminal or configuration, e.g. MAC address, hardware or software configuration or device fingerprint

Abstract

A transmission apparatus for optimizing a virtual private network operates by defragmenting and deduplicating transfer of variable sized blocks. A large data object is converted to a plurality of data paragraphs by a fingerprinting method. Each data paragraph is cached and hashed. The hashes are transmitted to at least one satellite apparatus. Only data paragraphs which are not previously cached at each satellite are transferred.

Claims

1. An transmission apparatus comprised of:

a circuit for to generate a data paragraph, a hash, and a remainder,

a satellite cache store,

a satellite transfer diary store, and

a circuit for to pack a plurality of hashes and a remainder into a packet, the circuits communicatively coupled to each other circuit.

2. The transmission apparatus of claim 1 further comprising

a circuit for transmission of a pending transfer,

a circuit for to determine when data paragraphs corresponding to hashes are located at primary cache store, and

at least one network interface, the circuits and network interface communicatively coupled to each other.

3. The transmission apparatus of claim 2 wherein the circuit for to generate a data paragraph, a hash, and a remainder is coupled to the satellite cache store whereby a data paragraph is stored corresponding to each hash, and the circuit for to generate a data paragraph, a hash, and a remainder is coupled to the satellite transfer diary store whereby the reception apparatus, the hash, and the status of the transfer of the data paragraph to the reception apparatus is recorded wherein status comprises a past date or pending, and the circuit for to generate a data paragraph, a hash, and a remainder is coupled to a circuit to pack hashes and a remainder into a data object integration packet addressed to a reception apparatus, whereby duplicative transfer of a data paragraph is avoided if it is already stored at the reception apparatus.

4. The transmission apparatus of claim 2 wherein the circuit for to generate a data paragraph, a hash, and a remainder comprises a circuit to select a string between a minimum length and a maximum length by computing a fingerprint and matching selected bits of the fingerprint to a certain mask by reading from the beginning of a data object or from the end of the previous data paragraph.

5. The apparatus of claim 4 further comprising a data paragraph cache store and a transfer diary story whereby data paragraphs transmitted from the apparatus can be reused in receiving incoming data objects.

6. The transmission apparatus of claim 2 wherein the circuit for to generate a data paragraph, a hash, and a remainder comprises a circuit to compute an SHA1 value on a variable length string.

7. The transmission apparatus of claim 2 wherein the circuit for to generate a data paragraph, a hash, and a remainder comprises a circuit to compute an MD5 value on a variable length string.

8. The transmission apparatus of claim 2 further comprising a circuit configured to transmit a hash to a satellite apparatus and to receive from the satellite apparatus if the transmission of a data paragraph corresponding to the hash is pending or past and further configured to transmit the data paragraph on the condition that the transmission is pending.

9. The transmission apparatus of claim 2 wherein the circuit to determine a data paragraph computes a low cost fingerprint cumulatively from the start of a string until certain bits of the fingerprint trigger an end of paragraph event and determination of the next paragraph begins.

10. The transmission apparatus of claim 2 wherein the circuit to determine a data paragraph triggers when a maximum size string is reached or a remainder triggers when the end of a data object is reached.

11. A method for operating a transmission apparatus coupled to a local area network and coupled to a wide area network, the apparatus comprising:

a circuit for to generate a data paragraph, a hash, and a remainder, a satellite cache store, a satellite transfer diary store, and a circuit for to pack a plurality of hashes and a remainder into a packet;

the method comprising;

receiving a data object,

generating at least one data paragraph,

computing a hash for each data paragraph,

determining a remainder,

storing a data paragraph into a primary cache store if the hash is determined to be new,

storing a record into a satellite transfer diary of the reception apparatus for each data paragraph, the hash, and the status of the transfer of the data paragraph to the reception apparatus, and

transferring at least one hash and a remainder to a circuit to pack a data object integration packet.

13. The method of claim 11 further:

reading a pending status for transfer of a data paragraph, transferring a data paragraph from a primary cache store to a satellite apparatus,

updating the status of the record in satellite transfer diary store from pending to past,

determining that all data paragraphs required for data object integration are stored at the satellite cache store, and

enabling transmission of a data object integration packet to the reception apparatus.

15. The method of claim 11 further comprising the step of synchronizing at least one satellite data paragraph cache store with the primary data paragraph cache store in anticipation of future data transfers.

16. The method of claim 11 wherein computing a hash comprises:

computing an SHA1 value on a variable length string.

17. The method of claim 11 wherein computing a hash comprises:

computing an MD5 value on a variable length string.

18. The method of claim 11 further comprising steps within the circuit for to generate a data paragraph, a hash, and a remainder comprising computing a fingerprint and determining a data paragraph on the occurrence of a certain string being matched by a masked fingerprint or a maximum length being reached.

19. The method of claim 11 further comprising steps within the circuit for to generate a data paragraph, a hash, and a remainder comprising determining a data paragraph by using digital signal processing detection of a repeating pattern.

20. The method of claim 11 further comprising steps within the circuit for to generate a data paragraph, a hash, and a remainder comprising selecting a plurality of data paragraphs from the start of a data object and on the condition that no more data paragraphs can be selected, assigning the rest of the data object as a remainder and transferring the hashes computed for each data paragraph and the remainder to a circuit for packing a data object integration packet addressed to the reception apparatus.

12. The method of claim 12 wherein generating at least one data paragraph comprises:

selecting a string between a minimum length and a maximum length by computing a fingerprint and

matching selected bits of the fingerprint to a certain mask by reading from the beginning of a data object or from the end of the previous data paragraph.

14. The method of claim 12 further comprising;

storing a data paragraph corresponding to each new hash,

recording a status of transmission of each paragraph to each reception apparatus, and

packing a data integration packet with a remainder and at least one hash of a data paragraph for each data object.