Transparent optimization for transmission control protocol initial session establishment

• US 20050135250A1
• Filed: 11/04/2004
• Published: 06/23/2005
• Est. Priority Date: 11/05/2003
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Singh, Balraj, Singh, Amit P., Paxson, Vern
• Granted Patent: US 7,058,058 B2
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures

Abstract

A system and method that optimizes transmission control protocol (TCP) initial session establishment without intruding upon TCP'"'"'s core algorithms. TCP'"'"'s initially session establishment is accelerated by locally processing a source'"'"'s initial TCP request within the source'"'"'s local area network (LAN). A control module relatively near the source'"'"'s local area network (LAN) and another control module relatively near a destination'"'"'s LAN are utilized to complete the initial TCP session establishment within the source and the destination'"'"'s respective LANs, thereby substantially eliminating the first round-trip time delay before the actual data flow begins. The first application-layer data packet thus can be transmitted at substantially the same time as the initial TCP request.

Claims

1. A method for optimizing an initial transmission control protocol (TCP) session establishment between a source and a destination comprising the steps of:

receiving a synchronization packet from the source;

generating a synthesized synchronization-acknowledgment packet including information of the destination in response to the received synchronization packet;

sending the synthesized synchronization-acknowledgment packet to the source; and

sending the synchronization packet to the destination.

2. The method of claim 1, wherein the step of receiving the synchronization packet from the source comprises:

receiving, at a location relatively near the source, the synchronization packet from the source.

3. The method of claim 2 wherein the step of sending the synchronization packet to the destination comprises:

characterizing the synchronization packet as desiring processing; and

sending the characterized synchronization packet to the destination.

4. The method of claim 3, further comprising the steps of:

receiving, at the location relatively near the source, an acknowledgment packet from the source;

receiving, at the location relatively near the source, a data packet from the source before receiving a synchronization-acknowledgment packet from the destination;

characterizing the received data packet as desiring processing; and

sending the characterized data packet to the destination.

5. The method of claim 3, wherein the information of the destination includes a network address, a TCP option combination, and a synthesized sequence number of the destination.

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

receiving, at a location relatively near the destination, the characterized synchronization packet;

removing the characterization from the received synchronization packet; and

sending the synchronization packet without the characterization to the destination.

7. The method of claim 6, further comprising the steps of:

receiving, at the location relatively near the destination, a characterized data packet from the source before receiving a synchronization-acknowledgment packet from the destination;

storing the characterized data packet;

receiving, at the location relatively near the destination, the synchronization-acknowledgment packet from the destination;

removing the characterization from the stored data packet;

determining an adjustment number based on the received synchronization-acknowledgment packet;

adjusting the data packet as a function of the determined adjustment number; and

sending the adjusted data packet without the characterization to the destination.

8. The method of claim 7, wherein the step of determining the adjustment number comprises the steps of:

identifying a sequence number used by the destination; and

subtracting the identified sequence number used by the destination from the synthesized sequence number.

9. The method of claim 7, wherein the step of adjusting the data packet comprises the step of:

subtracting the determined adjustment number from an acknowledgment number of the data packet.

10. The method of claim 6, further comprising the steps of:

receiving, at the location relatively near the destination, a synchronization-acknowledgment packet from the destination;

determining an adjustment number based on the received synchronization-acknowledgment packet;

receiving, at the location relatively near the destination, a data packet from the source;

adjusting the received data packet by subtracting the determined adjustment number from an acknowledgment number of the data packet; and

sending the adjusted data packet to the destination.

11. The method of claim 6, further comprising the steps of:

receiving, at the location relatively near the source, a data packet from the destination before receiving a synchronization-acknowledgment packet from the destination;

storing the received data packet;

receiving, at the location relatively near the source, the synchronization-acknowledgment packet from the destination;

determining an adjustment number based on the received synchronization-acknowledgment packet;

adjusting the stored data packet by adding the determined adjustment number to a sequence number of the data packet; and

sending the adjusted data packet to the source.

12. The method of claim 6, further comprising the steps of:

receiving, at the location relatively near the source, a synchronization-acknowledgment packet from the destination;

determining an adjustment number based on the received synchronization-acknowledgment packet;

receiving, at the location relatively near the source, a data packet from the source;

adjusting the received data packet by subtracting the determined adjustment number from an acknowledgment number of the data packet;

sending the adjusted data packet to the destination.

13. The method of claim 6, further comprising the steps of:

receiving, at the location relatively near the source, a synchronization-acknowledgment packet from the destination;

determining an adjustment number based on the received synchronization-acknowledgment packet;

receiving, at the location relatively near the source, a data packet from the destination;

adjusting the received data packet by adding the determined adjustment number to a sequence number of the data packet;

sending the adjusted data packet to the source.

14. The method of claim 1, further comprising the steps of:

observing, before generating the synthesized synchronization-acknowledgment packet, one or more responses of the destination to one or more synchronization packets sent by the source to the destination;

identifying one or more network addresses and TCP option combinations from the responses of the destination;

storing the identified one or more network addresses and TCP option combinations in a database; and

determining if the stored one or more network addresses and TCP option combinations are consistent; and

allowing the generation of the synthesized synchronization-acknowledgment packet if the stored one or more network addresses and TCP option combinations are consistent.

15. The method of claim 14, further comprising the steps of:

receiving a synchronization-acknowledgment packet from the destination after generating the synthesized synchronization-acknowledgment packet;

determining if the destination'"'"'s network address and TCP option combination as indicated in the received synchronization-acknowledgment packet are consistent with the one or more network addresses and TCP option combinations stored in the database; and

observing one or more further responses of the destination to one or more further synchronization packets sent by the source to determine a correct network address and TCP option combination of the destination.

16. A system for optimizing an initial transmission control protocol (TCP) session establishment between a source and a destination comprising:

a first control module for;

receiving a synchronization packet from the source;

generating a synthesized synchronization-acknowledgment packet including information of the destination in response to the received synchronization packet;

sending the synthesized synchronization-acknowledgment packet to the source; and

sending the synchronization packet to the destination.

17. The system of claim 16, wherein the first control module is associated with the source.

18. The system of claim 17, wherein the first control module characterizes the synchronization packet as desiring processing before sending the synchronization packet to the destination.

19. The system of claim 18, wherein the first control module:

receives a data packet from the source before receiving a synchronization-acknowledgment packet from the destination;

characterizes the received data packet as desiring processing; and

sends the characterized data packet to the destination.

20. The system of claim 18, wherein the information of the destination includes a network address, a TCP option combination, and a synthesized sequence number of the destination.

21. The system of claim 20, further comprising:

a second control module associated with the destination for;

receiving the characterized synchronization packet;

removing the characterization of the received synchronization packet; and

sending the synchronization packet to the destination without the characterization.

22. The system of claim 21, wherein the second control module:

receives a characterized application-layer packet from the source before receiving a synchronization-acknowledgment packet from the destination;

stores the characterized data packet;

receives the synchronization-acknowledgment packet from the destination;

removes the characterization from the stored data packet;

determines an adjustment number based on the received synchronization-acknowledgment packet;

adjusts the data packet as a function of the determined adjustment number; and

sends the adjusted data packet without the characterization to the destination.

23. The system of claim 22, wherein the second control module determines the adjustment number by:

identifying a sequence number used by the destination; and

subtracting the identified sequence number used by the destination from the synthesized sequence number.

24. The system of claim 22, wherein the second control module adjusts the data packet by:

subtracting the determined adjustment number from an acknowledgment number of the data packet.

25. The system of claim 21, wherein the second control module:

receives a synchronization-acknowledgment packet from the destination;

determines an adjustment number based on the received synchronization-acknowledgment packet;

receives a data packet from the source;

adjusts the received data packet by subtracting the determined adjustment number from an acknowledgment number of the data packet; and

sends the adjusted data packet to the destination.

26. The system of claim 21, wherein the first control module:

receives a data packet from the destination before receiving a synchronization-acknowledgment packet from the destination;

stores the received data packet;

receives the synchronization-acknowledgment packet from the destination;

determines an adjustment number based on the received synchronization-acknowledgment packet;

adjusts the stored data packet by adding the determined adjustment number to a sequence number of the data packet; and

sends the adjusted data packet to the source.

27. The system of claim 21, wherein the first control module:

receives a synchronization-acknowledgment packet from the destination;

determines an adjustment number based on the received synchronization-acknowledgment packet;

receives a data packet from the source;

adjusts the received data packet by subtracting the determined adjustment number from an acknowledgment number of the data packet;

sends the adjusted data packet to the destination.

28. The system of claim 21, wherein the first control module:

receives a synchronization-acknowledgment packet from the destination;

determines an adjustment number based on the received synchronization-acknowledgment packet;

receives a data packet from the destination;

adjusts the received data packet by adding the determined adjustment number to a sequence number of the data packet;

sends the adjusted data packet to the source.

29. The system of claim 16, wherein the first control module:

observes, before generating the synthesized synchronization-acknowledgment packet, one or more responses of the destination to one or more synchronization packets sent by the source to the destination;

identifies one or more network addresses and TCP option combinations from the responses of the destination;

stores the identified one or more network addresses and TCP option combinations in a database; and

determines if the stored one or more network addresses and TCP option combinations are consistent; and

allows the generation of the synthesized synchronization-acknowledgment packet if the stored one or more network addresses and TCP option combinations are consistent.

30. The system of claim 29, wherein the first control module:

receives a synchronization-acknowledgment packet from the destination after generating the synthesized synchronization-acknowledgment packet;

determines if the destination'"'"'s network address and TCP option combination as indicated in the received synchronization-acknowledgment packet are consistent with the one or more network addresses and TCP option combinations stored in the database; and

observes one or more further responses of the destination to one or more further synchronization packets sent by the source to determine a correct network address and TCP option combination of the destination.