Window flow control with common time reference

• US 20030174700A1
• Filed: 03/17/2003
• Published: 09/18/2003
• Est. Priority Date: 03/16/2002
• Status: Active Grant

• Current Assignee: Attestwave LLC (Jeffrey M. Gross)
• Original Assignee: Trustedflow Systems, Inc.
• Inventors: Ofek, Yoram, Baldi, Mario
• Granted Patent: US 7,307,989 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: G06F 21/14 against software analysis or reverse engineering, e.g. by obfuscation
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 47/27 Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 63/0227 Filtering policies mail message filtering H04L51/212
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• 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 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: Y04S 40/20 Information technology specific aspects, e.g. CAD, simulation, modelling, system security
• CPC Class Codes: Y10S 707/99939 Privileged access

Abstract

This invention relates generally to a method and apparatus for timely forwarding, discarding, and delivering data packets over the network and to their destination nodes and the optimization of data transfer throughput through the network. The timely forwarding and discarding are possible thanks to the standard global common time reference (CTR) that is known as UTC (Coordinated Universal Time). UTC is available from GPS (Global Positioning System), Galileo, and GLONASS (Global Navigation Satellite System). Data transfer throughput optimization is pursued by taking advantage of the timely forwarding and discarding properties to improve the data packets transfer flow control mechanisms, such as the sliding window re-sizing algorithm implemented by the widely deployed Transmission Control Protocol (TCP).

Claims

1. A method of data packet transmission control for controlling communications of data packets between a first node and a second node, a UTC (Universal Coordinated Time) signal coupled to each of the first node and the second node, wherein the UTC signal is comprised of UTC seconds which are divided into a predefined number of UTC time-frames, the method comprising:

sending data packets from the first node to the second node within the UTC time-frames;

receiving the data packets at the second node after a first defined delay;

defining UTR (unique time reference) time-frames at the second node representative of the UTC time-frames delayed by the first defined delay;

temporal mapping the UTR time-frames to respective ones of the UTC time-frames responsive to the UTC signal and to the first defined delay; and

outputting the data packets from the second node after a predefined number of UTC time-frames responsive to the UTC signal and to the temporal mapping.

2. The method as in claim 1, further comprising:

defining each of the UTC and UTR time-frames as respectively further comprised of UTC and UTR time-frame delimiters (TFDs), wherein the temporal mapping is responsive to the UTR time-frame delimiters.

3. The method as in claim 1, further comprising:

assigning and associating a time-stamp to the data packets at the sending, responsive to the UTC, wherein the temporal mapping is responsive to the time-stamp.

4. The method as in claim 2, further comprising:

defining the UTR time-frames as further comprised of the UTR time-frame delimiters, wherein the UTR time-frame delimiters are further comprised of a time-stamp assigned to the respective UTC time-frame delimiter at the sending, responsive to the UTC, wherein the temporal mapping is responsive to the time-stamp.

5. The method as in claim 1, wherein the forwarding further comprises:

counting data units within the data packets to be forwarded to determine a data unit count;

discarding selected ones of the data packets responsive to the respective data unit count exceeding a predefined number.

6. The method as in claim 5, further comprising:

randomly selecting the selected ones of the data packets to be discarded, until the respective data unit count is less than a second predefined number.

7. The method as in claim 5, wherein each of the data packets is further comprised of a header portion, the method further comprising:

selecting the selected ones of the data packets to be discarded responsive to the respective header portion, until the respective data unit count is less that a second redefined number.

8. The method as in claim 7, wherein the header portion is further comprised of at least one of a priority field, type of service field, cell loss priority field, hop count field, time to live field, differentiated services field.

9. The method as in claim 1, further comprising:

choosing the predefined number of UTC time-frames from a set of predefined numbers of UTC time-frames.

10. The method as in claim 9, wherein the communications of data packets from the second node is over a predefined number of N+1 additional nodes, the method further comprising:

summing the predefined number of UTC time-frames for all of the first, and not the additional, nodes and the second node, to define a summed, predefined number of UTC time-frames and

wherein the choosing is responsive to the summed predefined number.

11. The method as in claim 1, wherein the outputting further comprises:

counting the data units within the data packets to be forwarded to determine a data unit count and

outputting an explicit congestion notification (ECN) signal responsive to respective data unit counts exceeding a predefined number.

12. The method as in claim 11, wherein the ECN signal is comprised of at least one of the following:

congestion time derived responsive to the UTC;

congestion level and the data unit count; and

IDs of dropped data packets.

13. The method as in claim 12, wherein the IDs of dropped data packets are at least one of:

source IP address, destination IP address, IP port number, source address, destination address, VCI label in ATM, VPI label in ATM, MPLS label, Ethernet MAC source address, Ethernet MAC destination address.

14. The method as in claim 11, further comprising:

controlling the transmission of data packets in a system between a first access point and a second access point on each side of a network;

receiving and storing incoming data packets to be transmitted from the first access point, assigning a packet time-stamp based on the then current UTC;

associating the packet time-stamp with the data packets to be transmitted;

transmitting the data packets to the second access point;

receiving and storing the data packets at the second access point;

computing a target packet arrival time responsive to the packet time-stamp for the respective data packet;

scheduling forwarding of the respective data packet responsive to the UTC and the target packet arrival time;

scheduling receiver acknowledgement processing for generating an acknowledgement signal back to the first access point responsive to the UTC and the target packet arrival time;

assigning and attaching the acknowledgement time-stamp to the acknowledgment signal, responsive to the UTC;

sending the acknowledgement signal to the first access point;

assigning a first window-size, defining a first number of data packets to be transmitted within a defined time period;

receiving and storing the acknowledgement signal;

computing a target acknowledgement arrival time responsive to the acknowledgement time-stamp and to the UTC; and

adaptively redefining the window-size responsive to the UTC and the target acknowledgment arrival time and the ECN signal.

15. The method as in claim 14, further comprising:

correlating at least one of the ECN signals,

wherein the adaptively redefining the window-size is responsive to at least one of;

the UTC and the target acknowledgment arrival time and selected ones of the ECN signals.

16. The method as in claim 11, further comprising:

controlling the transmission of data packets in a system between a first access point and a second access point on each side of a network;

receiving and storing incoming data packets to be transmitted from the first access point, assigning a packet time-stamp based on a then current UTC;

associating a future packet time-stamp with the data packets to be transmitted;

transmitting the data packets to the second access point;

assigning a first window-size, defining a first number of data packets to be transmitted within a defined time period; and

adaptively redefining the window-size responsive to the UTC and the ECN signal.

17. The method as in claim 16, further comprising:

storing the values of past window-sizes;

correlating the ECN signals with selected ones of past window-sizes;

wherein the adaptively redefining the window-size is responsive to at least one of;

the UTC and the target acknowledgment arrival time and the ECN signal.

18. A system of data packet transmission control for controlling communications of data packets between a first node and a second node, a UTC (Universal Coordinated Time) signal coupled to each of the first node and the second node, wherein the UTC signal is comprised of UTC seconds which are divided into a predefined number of UTC time-frames, the system comprising:

means for sending data packets from the first node to the second node within the UTC time-frames;

means for receiving the data packets at the second node after a first defined delay;

means for defining a UTR (unique time reference) time-frames at the second node representative of the UTC time-frames delayed by the first defined delay;

a temporal mapping controller for mapping the UTR time-frames to respective ones of the UTC time-frames responsive to the UTC signal and to the first defined delay; and

means for outputting the data packets from the second node after a predefined number of UTC time-frames responsive to the UTC signal and to the temporal mapping.

19. The system as in claim 18, wherein each of the UTC and UTR time-frames are respectively further comprised of UTC and UTR time-frame delimiters (TFDs), wherein the temporal mapping is responsive to the UTR time-frame delimiters.

20. The system as in claim 18, wherein the means for sending data packets is further comprised of:

means for assigning and associating a time-stamp to the data packets by the means for sending, responsive to the UTC, wherein the temporal mapping controller is responsive to the time-stamp.

21. The system as in claim 19, wherein the UTR time-frames are further comprised of the UTR time-frame delimiters (TFDs), wherein the UTR time-frame delimiters are further comprised of a time-stamp assigned to the respective UTC time-frame delimiter by the means for sending, responsive to the UTC, wherein the temporal mapping controller is responsive to the time-stamp.

22. The system as in claim 18, wherein the forwarding further comprises:

a best effort scheduling controller counting data units within the data packets to be forwarded to determine a data unit count;

a select buffer and time-driven early random discard controller for discarding selected ones of the data packets responsive to the respective data unit count exceeding a predefined number.

23. The system as in claim 22,

wherein the select buffer and time-driven early random discard controller randomly selecting the selected ones of the data packets to be discarded, until the respective data unit count is less than a second predefined number.

24. The system as in claim 22, wherein each of the data packets is further comprised of a header portion, the system further comprising:

means for selecting the selected ones of the data packets to be discarded responsive to the respective header portion, until the respective data unit count is less that a second redefined number.

25. The system as in claim 24, wherein the header portion is further comprised of at least one of a priority field, type of service field, cell loss priority field, hop count field, time to live field, differentiated services field.

26. The system as in claim 18, further comprising:

means for choosing the predefined number of UTC time-frames from a set of predefined numbers of UTC time-frames.

27. The system as in claim 26, wherein the communications of data packets from the second node is over a predefined number of N+1 additional nodes, the method further comprising:

means for summing the predefined number of UTC time-frames for all of the first, and not the additional, nodes and the second node, to define a summed, predefined number of UTC time-frames; and

wherein the choosing is responsive to the summed predefined number.

28. The system as in claim 27, wherein the select buffer and time-driven early random discard controller is used to provides the means for summing the predefined number of UTC time-frames.

29. The system as in claim 27, wherein the summed predefined number is encoded into the data packet by the select buffer and time-driven early random discard controller.

30. The system as in claim 19, wherein the time-frame delimiter is at least one of the following:

a redundant serial codeword, an 8B/10B fiber channel redundant serial codeword, a 4B/5B FDDI redundant serial codeword, a pointer encoded in the SONET path overhead (POH), a pointer encoded in the SONET transport overhead (TOH), a position determined by counting data units, a control IP data packet, a control ATM cell, and a control MPLS data packet.

31. The system as in claim 18, wherein predefined number of the UTC time-frames are grouped to at least one of:

time cycles and super cycles.

32. A method for controlling the transmission of data packets in a system between a first access point and a second access point on each end of a network, coupled to a UTC (Universal Coordinated Time) signal, the method comprising:

receiving and storing incoming data packets to be transmitted from the first access point, assigning a packet time-stamp based on the then current UTC;

associating the packet time-stamp with the data packets to be transmitted;

transmitting the data packets to the second access point;

receiving and storing the data packets at the second access point;

computing a target packet arrival time responsive to the packet time-stamp for the respective data packet;

scheduling forwarding of the respective data packet responsive to the UTC signal and the target packet arrival time; and

scheduling receiver acknowledgement processing to generate an acknowledgement signal back to the first access point responsive to the UTC signal and the target packet arrival time.

33. The method as in claim 32, further comprising:

assigning and attaching an acknowledgement time-stamp to the acknowledgment signal, responsive to the UTC signal; and

sending the acknowledgement signal to the first access point.

34. The method as in claim 33, further comprising:

assigning a first window-size, defining a first number of data packets to be transmitted within a defined time period;

receiving and storing the acknowledgement signal;

computing a target acknowledgement arrival time responsive to the acknowledgement time-stamp and to the UTC signal; and

adaptively redefining the window-size responsive to the UTC signal and the target acknowledgment arrival time.

35. The method as in claim 32, further comprising:

assigning a packet-bound, defining an expected time delay between transmission from the first access point until the receiving acknowledgement processing; and

adapting the packet delay-bound, responsive to the UTC signal and the packet timestamp.

36. The method as in claim 34, further comprising:

assigning an acknowledgement arrival time to the acknowledgement signal as it is received; and

adaptively redefining the target acknowledgement arrival time responsive to the UTC signal, the time-stamp and the acknowledgement arrival time.

37. The method as in claim 34, further comprising:

assigning an acknowledgment delay-bound defining an expected time delay between the sending of the acknowledgement signal until adaptively redefining the window-size; and

adapting the acknowledgment delay-bound responsive to the UTC signal and the acknowledgement time-stamp.

38. A data packet communications control system for control of communications of data packets across a network between a first access point and a second access point, the system comprising:

means for receiving and storing incoming data packets to be transmitted from the first access point, and for assigning and associatively storing a packet time-stamp based on the then current UTC;

a time stamping subsystem for associating the future packet time-stamp with the data packets to be transmitted;

means for transmitting the data packets to the second access point;

means for receiving and storing the data packets at the second access point;

an adaptive packet jitter removal controller for computing a target packet arrival time responsive to the packet time-stamp for the respective data packet;

the adaptive packet jitter removal controller further comprising

means for scheduling forwarding of the respective data packet responsive to the UTC signal and the target packet arrival time; and

means for scheduling receiver acknowledgement processing by a receiver controller to generate an acknowledgement signal back to the first access point responsive to the UTC signal and the target packet arrival time.

39. The system as in claim 38, wherein the receiver controller further comprises means for assigning and attaching the acknowledgement time-stamp to the acknowledgment signal, responsive to the UTC signal, further comprising:

an ACK transmission subsystem comprising means for sending the acknowledgement signal to the first access point.

40. The system as in claim 39, further comprising:

a window controller for assigning a first window-size, defining a first number of data packets to be transmitted within a defined time period;

wherein the adaptive ACK jitter removal controller further comprises means for receiving and storing the acknowledgement signal and means for computing a target acknowledgement arrival time responsive to the acknowledgement time-stamp and to the UTC signal; and

wherein the window controller further comprises means for adaptively redefining the window-size responsive to the UTC signal and the target acknowledgment arrival time.

41. The system as in claim 38, wherein the adaptive packet jitter removal controller further comprises:

means for assigning a packet-bound, defining an expected time delay between transmission from the first access point until the receiver acknowledgement processing; and

means for adapting the packet delay-bound, responsive to the UTC signal and the packet time-stamp.

42. The system as in claim 40, wherein the adaptive ACK jitter removal controller further comprises:

means for assigning an acknowledgement arrival time to the acknowledgement signal as it is received; and

means for adaptively redefining the target acknowledgement arrival time responsive to the UTC signal, the time-stamp and the acknowledgement arrival time.

43. The system as in claim 40, wherein the adaptive ACK jitter removal controller further comprises:

means for assigning an acknowledgment delay-bound, defining and expected time delay between the sending of the acknowledgement signal until adaptively redefining the window-size; and

means for adapting the acknowledgment delay-bound responsive to the UTC signal and the acknowledgement time-stamp.