Shaping multimedia stream bit-rates to adapt to network conditions

• US 8,811,167 B2
• Filed: 02/24/2011
• Issued: 08/19/2014
• Est. Priority Date: 02/24/2011
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Khilnani, Sarat, Wu, Duanpei, Yang, Shih-cheng Stan
• Primary Examiner(s): Russell, Wanda Z
• Application Number:
  US13/034,244
• Publication Number:
  US 20120218887A1
• Time in Patent Office: 1,272 Days
• Field of Search: 370/230, 370/235, 370/252
• US Class Current: 370/230
• CPC Class Codes: H04L 12/1863 comprising mechanisms for improved reliability, e.g. status reports arrangements for detecting or preventing errors by carrying supervisory signal the return channel H04L1/16
• CPC Class Codes: H04L 43/0864 Round trip delays
• CPC Class Codes: H04L 43/0876 Network utilisation, e.g. volume of load or congestion level
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/17 Interaction among intermediate nodes, e.g. hop by hop
• CPC Class Codes: H04L 47/18 End to end
• CPC Class Codes: H04L 47/22 Traffic shaping

Abstract

An apparatus and methods are provided for shaping a transmit bit-rate of a multimedia stream to adapt to the bandwidth of network path on which the multimedia stream is sent between a source and destination. A condition indicative of a bandwidth of the network path is monitored, and at an intermediate point on the network path between the source and destination, the transmit bit-rate of the multimedia stream is adjusted to adapt to the condition indicative of the bandwidth of the path.

Claims

1. A method comprising:

monitoring a condition indicative of a bandwidth of a network path on which a multimedia stream is being sent from a source to a destination;

determining if the bandwidth has changed by at least a predetermined amount for a predetermined amount of time; and

responsive to determining that the bandwidth has changed by at least the predetermined amount for the predetermined amount of time, at an intermediate point between the source and the destination on the network path of the multimedia stream, adjusting a transmit bit-rate of the multimedia stream to adapt to the condition indicative of the bandwidth of the network path.

2. The method of claim 1, wherein monitoring and adjusting are performed at multiple intermediate points on different network paths between the source and the destination to separately adjust the transmit bit-rate at different intermediate points in order to adapt to conditions indicative of the bandwidth of the corresponding different network paths.

3. The method of claim 2, wherein monitoring and adjusting are performed at respective network devices at corresponding ones of the intermediate points on the different network paths.

4. The method of claim 1, wherein determining comprises determining when the bandwidth has decreased below the transmit bit-rate of the multimedia stream, and wherein adjusting comprises reducing the transmit bit-rate of the multimedia stream.

5. The method of claim 4, wherein adjusting comprises incrementally reducing the transmit bit-rate of the multimedia stream.

6. The method of claim 1, wherein determining comprises determining when the bandwidth has increased, and wherein adjusting comprises increasing the transmit bit-rate of the multimedia stream.

7. The method of claim 6, wherein adjusting comprises incrementally increasing the transmit bit-rate of the multimedia stream.

8. The method of claim 1, wherein monitoring the condition indicative of the bandwidth comprises receiving a real-time transport control protocol (RTCP) report.

9. The method of claim 8, wherein the RTCP report comprises at least one of a packet drop rate or a round trip delay.

10. The method of claim 1, wherein monitoring the condition indicative of the bandwidth comprises detecting a rate of packet retransmissions.

11. The method of claim 1, wherein monitoring the condition indicative of the bandwidth comprises detecting a transmission failure rate.

12. The method of claim 1, and further comprising determining when the bandwidth of the network path decreases by a predetermined amount, and adjusting comprises reducing the transmit bit-rate of the multimedia stream, and further comprising determining whether to further reduce or to increase the transmit bit-rate of the multimedia stream based on the bandwidth of the network path after the adjusting.

13. The method of claim 1, wherein monitoring of the condition indicative of the bandwidth comprises emulating real-time transport control protocol (RTCP) by transmitting packets to a second intermediary device and receiving packets from the second intermediary device.

14. An apparatus comprising:

a network interface unit configured to interface to a network;

a packet forwarding unit configured to receive and forward packets on a network path in the network; and

a controller configured to;

monitor a condition indicative of the bandwidth of the network path on which a multimedia stream is being sent from a source to a destination;

determine if the bandwidth has changed by a predetermined amount for a predetermined amount of time; and

responsive to determining that the bandwidth has changed by at least the predetermined amount for the predetermined amount of time, at an intermediate point between the source and the destination on the network path of the multimedia stream, adjust a transmit bit-rate of the multimedia stream to adapt to the condition indicative of the bandwidth of the network path.

15. The apparatus of claim 14, wherein the controller is configured to determine when the bandwidth has decreased below the transmit bit-rate of the multimedia stream, and to reduce the transmit bit-rate of the multimedia stream.

16. The apparatus of claim 14, wherein the controller is configured to determine when the bandwidth has increased, and to increase the transmit bit-rate of the multimedia stream.

17. The apparatus of claim 14, wherein the controller is configured to determine when the bandwidth of the network path decreases by a predetermined amount to reduce the transmit bit-rate of the multimedia stream, and to determine whether to further reduce or to increase the transmit bit-rate of the multimedia stream based on the bandwidth of the network path after making the adjustment to the transmit bit-rate.

18. The apparatus of claim 14, wherein the controller is configured to emulate real-time transport control protocol (RTCP).

19. One or more non-transitory computer readable storage media encoded with software comprising computer-executable instructions and when the software is executed operable to:

monitor a condition indicative of the bandwidth of a network path on which a multimedia stream is being sent from a source to a destination;

determine if the bandwidth has changed by at least a predetermined amount for a predetermined amount of time; and

responsive to determining that the bandwidth has changed by at least the predetermined amount for the predetermined amount of time, at an intermediate point between the source and the destination on the network path of the multimedia stream, adjust a transmit bit-rate of the multimedia stream based on the condition indicative of the bandwidth indication of the network path.

20. The non-transitory computer readable storage media of claim 19, wherein the instructions that are operable to determine when the bandwidth has changed comprise instructions operable to determine when the bandwidth has decreased, and wherein the instructions that are operable to adjust comprise instructions that are operable to reduce the transmit bit-rate of the multimedia stream.

21. The non-transitory computer readable storage media of claim 19, wherein the instructions that are operable to monitor the bandwidth comprise instructions that are operable to determine when the bandwidth of the network routing path decreases below the transmit bit-rate, and wherein the instructions that are operable to adjust comprise instructions that are operable to reduce the transmit bit-rate of the multimedia stream, and further comprising instructions that are operable to determine whether to further reduce or to increase the transmit bit-rate of the multimedia stream based on the bandwidth of the network routing path after making the adjustment.

22. The non-transitory computer readable storage media of claim 19, wherein the instructions that are operable to monitor the bandwidth comprise instructions that are operable to emulate real-time transport control protocol (RTCP).