Network delay control

• US 20050226156A1
• Filed: 02/08/2005
• Published: 10/13/2005
• Est. Priority Date: 04/13/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: RadioFrame Networks, Inc. (Motorola Solutions, Inc.)
• Inventors: Zhang, Yan, Keating, Pierce, Stevens, Bill
• Granted Patent: US 7,499,402 B2
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 43/0858 One way delays
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 67/62 Establishing a time schedule for servicing the requests
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols

Abstract

Controlling the flow of network traffic to avoid undesired delay in the transmission of timing sensitive packets is disclosed. A plurality of packets to be transmitted via a network transmission path is monitored. A time at which a timing sensitive packet will become available for transmission via the network transmission path is anticipated. The plurality of packets is controlled in light of the anticipated time so that packets other than the timing sensitive packet will not occupy the network transmission path at a time associated with the anticipated time. Approximating a maximum data transmission rate associated with a network transmission path by sending and analyzing receipt of a series of test packets is disclosed. Approximating a buffer size of a buffer associated with a network transmission path by sending and analyzing receipt of a series of test packets is disclosed.

Claims

1. A method of controlling network traffic, comprising:

monitoring a plurality of packets to be transmitted via a network transmission path;

anticipating a time at which a timing sensitive packet will become available for transmission via the network transmission path; and

controlling the plurality of packets in accordance the anticipated time so that the network transmission path will not be occupied by packets other than the timing sensitive packet at a time associated with the anticipated time.

2. A method of controlling network traffic as in claim 1 further comprising rate limiting the plurality of packets to be transmitted in accordance with an optimal data rate of the network transmission path.

3. A method of controlling network traffic as recited in claim 1, wherein the timing sensitive packet comprises a timing packet.

4. A method of controlling network traffic as recited in claim 1, wherein the time associated with the anticipated time comprises a time window determined based on the anticipated time.

5. A method of controlling network traffic as recited in claim 4, further comprising extending the time window in the event the timing sensitive packet does not arrive at the anticipated time.

6. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises clearing a memory associated with the network transmission path prior to the anticipated time.

7. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises clearing a memory associated with the network transmission path prior to the anticipated time so that the packet of a specific type is transmitted via the network transmission path without being buffered.

8. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises keeping packets other than the timing sensitive packet from being transmitted during a time window associated with the anticipated time.

9. A method of controlling network traffic as recited in claim 8, wherein the time window is associated with a timer.

10. A method of controlling network traffic as recited in claim 8, wherein the beginning of the time window is associated with setting a timer.

11. A method of controlling network traffic as recited in claim 8, wherein the end of the time window is associated with the expiration of a timer.

12. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises storing packets other than the timing sensitive packet in a memory.

13. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises determining a bandwidth of the network transmission path.

14. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises determining a bandwidth of the network transmission path and regulating the sending of data to the network transmission path so as to avoid significantly exceeding the network transmission path bandwidth.

15. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises sending a plurality of test packets via the network transmission path.

16. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises approximating a maximum data transmission rate associated with the network transmission path.

17. A method of controlling network traffic as recited in claim 16, wherein approximating a maximum data transmission rate associated with the network transmission path comprises:

sending a series of test packets at a known rate from a sending node to the network transmission path for transmission to a receiving node via the network transmission path;

determining how many of the packets comprising the series of test packets arrived at the receiving node; and

approximating the maximum data transmission rate associated with the network transmission path based at least in part on data associated with the packets, if any, that did not arrive at the receiving node.

18. A method of controlling network traffic as recited in claim 17, wherein approximating the maximum data transmission rate associated with the network transmission path based at least in part on data associated with the packets, if any, that did not arrive at the receiving node comprises approximating the maximum data transmission rate associated with the network transmission path based at least in part on the number of packets that did not arrive.

19. A method of controlling network traffic as recited in claim 17, wherein approximating the maximum data transmission rate associated with the network transmission path based at least in part on data associated with the packets, if any, that did not arrive at the receiving node comprises approximating the maximum data transmission rate associated with the network transmission path based at least in part on an identifier associated with a packet that did not arrive.

20. A method of controlling network traffic as recited in claim 17, wherein approximating the maximum data transmission rate associated with the network transmission path based at least in part on data associated with the packets, if any, that did not arrive at the receiving node comprises:

identifying a first missing packet in the series as received at the receiving node;

determining the number of packets in a subset that includes the first missing packet and the packets of the series that follow the first missing packet in order; and

comparing the total number of packets in the subset to the number of packets in the subset that arrived at the receiving node.

21. A method of controlling network traffic as recited in claim 20, wherein approximating the maximum data transmission rate associated with the network transmission path based at least in part on data associated with the packets, if any, that did not arrive at the receiving node further comprises dividing the number of packets in the subset that arrived at the receiving node by the total number of packets in the subset and multiplying the result by the known rate.

22. A method of controlling network traffic as recited in claim 17, wherein the known rate comprises a maximum data transmission rate associated with the sending node.

23. A method of controlling network traffic as recited in claim 17, wherein it is determined that the maximum data transmission rate associated with the network transmission path equals or exceeds the known rate.

24. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises determining a buffer size of a buffer associated with the network transmission path.

25. A method of controlling network traffic as recited in claim 24, wherein determining a buffer size comprises:

sending a series of test packets at a known rate from a sending node to the network transmission path for transmission to a receiving node via the network transmission path;

determining whether all of the packets comprising the series of test packets arrived at the receiving node; and

in the event it is determined that not all of the packets comprising the series arrived at the receiving node;

identifying a first missing packet in the series that did not arrive;

determining how many packets precede the first missing packet in the series; and

approximating the buffer size based at least in part on how many packets precede the first missing packet in the series.

26. A method of controlling network traffic as recited in claim 25, wherein approximating the buffer size further comprises approximating the buffer size based at least in part on a maximum data transmission rate associated with the network transmission path.

27. A method of controlling network traffic as recited in claim 25, wherein approximating the buffer size further comprises approximating the buffer size based at least in part on an average packet size associated with the series.

28. A method of controlling network traffic as recited in claim 25, wherein approximating the buffer size based at least in part on how many packets precede the first missing packet in the series comprises subtracting from an amount of data associated with the packets that precede the first missing packet in the series the approximate amount of data transmitted by the network transmission path to the receiving node during a period in which the packets that precede the first missing packet in the series were sent.

29. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises determining a buffer size of a buffer associated with the network transmission path and setting a time window based at least in part on the buffer size.

30. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises determining a buffer size of a buffer associated with the network transmission path and dynamically adjusting a time window based on incoming packet length and amount of data currently in the buffer.

31. A method of controlling network traffic as recited in claim 1, wherein controlling the flow of packets to the network transmission path comprises approximating on a running basis the amount of data occupying the network transmission path at any given time.

32. A method of controlling network traffic as recited in claim 31, wherein approximating on a running basis the amount of data occupying the network transmission path at any given time comprises incrementing a propagation timer each time a packet is sent to the network transmission path and decrementing the propagation timer over time based on a data transmission rate associated with the network transmission path.

33. A method of controlling network traffic as recited in claim 31, wherein controlling the flow of packets to the network transmission path further comprises preventing a non-timing sensitive packet from being sent if adding the non-timing sensitive packet to the data occupying the network transmission path would result in the capacity of a buffer size associated with a buffer associated with the network transmission path being exceeded.

34. A method of controlling network traffic as recited in claim 33, wherein controlling the flow of packets to the network transmission path further comprises preventing a non-timing sensitive packet from being sent if adding the non-timing sensitive packet to the data occupying the network transmission path would result in the network transmission path not being available to transmit the timing sensitive packet with a substantially minimum delay at a time associated with the anticipated time.

35. A method of controlling network traffic as recited in claim 31, wherein controlling the flow of packets to the network transmission path further comprises preventing a non-timing sensitive packet from being sent if adding the non-timing sensitive packet to the data occupying the network transmission path would result in the network transmission path not being available to transmit the timing sensitive packet with a substantially minimum delay at a time associated with the anticipated time.

36. A method of controlling network traffic as recited in claim 1, wherein the timing sensitive packet comprises a field indicating a time at which a next timing sensitive packet will become available.

37. A method of controlling network traffic as recited in claim 1, wherein the timing sensitive packet comprises a field used to distinguish the timing sensitive packet from non timing sensitive packets.

38. A method of controlling network traffic as recited in claim 1, wherein the timing sensitive packet is associated with a particular function and comprises a field used to distinguish the timing sensitive packet from timing sensitive packets not associated with said function.

39. A method of controlling network traffic as recited in claim 1, wherein the timing sensitive packet comprises a field indicating a priority associated with the timing sensitive packet.

40. A method of controlling network traffic as recited in claim 1, wherein the timing sensitive packet comprises synchronization information.

41. A method of controlling network traffic as recited in claim 1, wherein the timing sensitive packet comprises frequency information used to frequency lock a receiving node.

42. A method of controlling network traffic as recited in claim 1, wherein the timing sensitive packet comprises a wireless protocol packet.

43. A method of controlling network traffic as recited in claim 1, wherein the timing sensitive packet comprises voice data.

44. A method of controlling network traffic as recited in claim 1, wherein the timing sensitive packet comprises streamed video data.

45. A system for controlling network traffic, comprising:

an interface for transmitting a plurality of packets via a network transmission path; and

a network delay controller coupled to the interface, configured to;

monitor a plurality of packets to be transmitted via a network transmission path;

anticipate a time at which a timing sensitive packet will become available for transmission via the network transmission path; and

control a flow of packets to the network transmission path in light of the anticipated time so that the network transmission path will not be occupied by packets other than the timing sensitive packet at a time associated with the anticipated time.

46. A computer program product for controlling network traffic, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

monitoring a plurality of packets to be transmitted via a network transmission path;

anticipating a time at which a timing sensitive packet will become available for transmission via the network transmission path; and

controlling a flow of packets to the network transmission path in light of the anticipated time so that the network transmission path will not be occupied by packets other than the timing sensitive packet at a time associated with the anticipated time.

47. A method of approximating a maximum data transmission rate associated with a network transmission path, comprising:

sending a series of test packets at a known rate from a sending node to the network transmission path for transmission to a receiving node via the network transmission path;

determining whether all of the packets comprising the series of test packets arrived at the receiving node; and

approximating the maximum data transmission rate associated with the network transmission path based at least in part on data associated with the packets, if any, that did not arrive at the receiving node.

48. A system for approximating a maximum data transmission rate associated with a network transmission path, comprising:

a send interface configured to send a series of test packets at a known rate from a sending node to the network transmission path for transmission to a receiving node via the network transmission path; and

a processor configured to determine whether all of the packets comprising the series of test packets arrived at the receiving node and approximate the maximum data transmission rate associated with the network transmission path based at least in part on data associated with the packets, if any, that did not arrive at the receiving node.

49. A computer program product for approximating a maximum data transmission rate associated with a network transmission path, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

sending a series of test packets at a known rate from a sending node to the network transmission path for transmission to a receiving node via the network transmission path;

determining whether all of the packets comprising the series of test packets arrived at the receiving node; and

approximating the maximum data transmission rate associated with the network transmission path based at least in part on data associated with the packets, if any, that did not arrive at the receiving node.

50. A method of approximating a buffer size associated with a buffer associated with a network transmission path, comprising:

sending a series of test packets at a known rate from a sending node to the network transmission path for transmission to a receiving node via the network transmission path;

determining whether all of the packets comprising the series of test packets arrived at the receiving node; and

in the event it is determined that not all of the packets comprising the series arrived at the receiving node;

identifying a first missing packet in the series that did not arrive;

determining how many packets precede the first missing packet in the series; and

approximating the buffer size based at least in part on how many packets precede the first missing packet in the series.

51. A system for approximating a buffer size associated with a buffer associated with a network transmission path, comprising:

a send interface configured to send a series of test packets at a known rate from a sending node to the network transmission path for transmission to a receiving node via the network transmission path; and

a processor configured to determine whether all of the packets comprising the series of test packets arrived at the receiving node and, in the event it is determined that not all of the packets comprising the series arrived at the receiving node;

identify a first missing packet in the series that did not arrive;

determine how many packets precede the first missing packet in the series; and

approximate the buffer size based at least in part on how many packets precede the first missing packet in the series.

52. A computer program product for approximating a buffer size associated with a buffer associated with a network transmission path, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

sending a series of test packets at a known rate from a sending node to the network transmission path for transmission to a receiving node via the network transmission path;

determining whether all of the packets comprising the series of test packets arrived at the receiving node; and

in the event it is determined that not all of the packets comprising the series arrived at the receiving node;

identifying a first missing packet in the series that did not arrive;

determining how many packets precede the first missing packet in the series; and

approximating the buffer size based at least in part on how many packets precede the first missing packet in the series.