Dynamically adjusting bandwidth usage among subscriber streams

• US 8,654,638 B2
• Filed: 12/19/2006
• Issued: 02/18/2014
• Est. Priority Date: 12/19/2006
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta LLC (Cisco Systems, Inc.)
• Inventors: Godlewski, Marcin
• Primary Examiner(s): Mian, Omer S
• Application Number:
  US11/612,524
• Publication Number:
  US 20080144660A1
• Time in Patent Office: 2,618 Days
• Field of Search: 370/468, 370/232, 370/231, 370/233, 370/234, 370/230.1, 370/230
• US Class Current: 370/231
• CPC Class Codes: H04L 1/187 Details of sliding window management
• 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 67/60 Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources admission control or resource allocation H04L47/70
• 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
• CPC Class Codes: H04L 69/165 Combined use of TCP and UDP protocols; selection criteria therefor

Abstract

Systems and methods are disclosed for adjusting bandwidth of streams carried on a subscriber loop. One exemplary method comprises the steps of: determining bandwidth in use on a subscriber loop; selecting, for adjustment, at least one of a plurality of TCP streams carried on the subscriber loop; and adjusting at least one flow control parameter of the selected TCP stream based on the bandwidth in use. An exemplary multimedia terminal adapter (MTA) comprises memory and a processor. The memory stores program code, and the code programs the processor to enable the MTA to: determine bandwidth in use on a subscriber loop; select, for adjustment, at least one of a plurality of TCP streams carried on the subscriber loop; and adjust at least one flow control parameter of the selected TCP stream based on the bandwidth in use.

Claims

1. A method, performed in a multimedia terminal adapter (MTA), of adjusting bandwidth of at least one of a plurality of Transport Control Protocol (TCP) streams carried on a subscriber loop, the method comprising:

determining whether at least one user data protocol (UDP) session comprising at least one UDP stream is active on the subscriber loop;

in response to the determination that the at least one UDP session is active on the subscriber loop, sending a query to a bandwidth monitor, wherein the query requests a current total bandwidth usage and a relative distribution of bandwidth usage among the plurality of TCP streams;

receiving a notification from the bandwidth monitor indicating the current total bandwidth usage and the relative distribution of bandwidth usage among the plurality of TCP streams on the subscriber loop;

comparing the current total bandwidth usage with a predetermined threshold;

in response to the current bandwidth usage surpassing the predetermined threshold, selecting at least one of the plurality of TCP streams based on the relative distribution of the bandwidth carried on the subscriber loop, wherein the selected at least one of the TCP streams having the highest bandwidth usage among the plurality of TCP streams; and

reducing the bandwidth usage for the selected at least one of the plurality of TCP streams by adjusting at least one flow control parameter for the selected at least one of the plurality of TCP streams, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises adjusting at least one of;

a sliding window size and an acknowledgement delay.

2. The method of claim 1, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises decreasing the sliding window size of the selected TCP stream.

3. The method of claim 1, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises increasing the acknowledgement delay of the selected TCP stream.

10. The method of claim 1, further comprising:

determining when the UDP session on the MTA has ended; and

suspending, upon termination of the UDP session, the adjusting of the at least one flow control parameter.

11. The method of claim 1, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises terminating the selected at least one of the plurality of TCP streams.

12. The method of claim 10, further comprising:

determining the current amount of bandwidth in use after the end of the UDP session,

readjusting the at least one flow parameter of the at least one of the plurality of TCP streams based on the determined current bandwidth after the end of the UDP session.

13. The MTA of claim 12, wherein readjusting the at least one flow parameter of the at least one of the plurality of TCP streams based on the determined current bandwidth comprises undoing the adjustment of the at least one flow parameter for the at least one of the plurality of TCP stream.

4. A multimedia terminal adapter (MTA) comprising:

memory having stored thereon a program code; and

a processor that is programmed by at least the program code to enable the MTA to;

determine whether at least one user data protocol (UDP) session comprising at least one UDP stream is active on a subscriber loop;

in response to the determination that the at least one UDP session is active on the subscriber loop, send a query to a bandwidth monitor, wherein the query requests a current total bandwidth usage, and a relative distribution of bandwidth usage among a plurality of Transport Control Protocol (TCP) steams carried on the subscriber loop;

receive a notification from the bandwidth monitor indicative that the current total bandwidth usage and the relative distribution of bandwidth usage among the plurality of TCP streams on the subscriber loop has crossed a threshold;

compare the current total bandwidth usage with a predetermined threshold;

in response to the current bandwidth usage surpassing the predetermined threshold, select at least one of the plurality of TCP streams based on the relative distribution of the bandwidth carried on the subscriber loop, wherein the selected at least one of the plurality of TCP streams having the highest bandwidth usage among the plurality of TCP streams; and

reduce the bandwidth usage for the selected at least one of the plurality of TCP streams by adjusting at least one flow control parameter for the selected at least one of the plurality of TCP streams, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises adjusting at least one of;

a sliding window size and an acknowledgement delay.

5. The MTA of claim 4, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises decreasing the sliding window size of the selected TCP stream.

6. The MTA of claim 4, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises increasing the acknowledgement delay of the selected TCP stream.

14. The MTA of claim 4, wherein the processor is further programmed to enable the MTA to:

periodically query a broadband Media Access Control (MAC) layer instance in order to determine a number of bytes received by the broadband MAC layer instance on at least each of the plurality of TCP streams; and

compute the total current bandwidth in use on the subscriber loop based on the number of bytes received by the broadband MAC layer instance.

15. The MTA of claim 5, wherein decreasing the sliding window size of the selected TCP stream comprises decreasing the sliding window size by half.

16. The MTA of claim 6, wherein increasing the acknowledgement delay of the selected TCP stream comprises increasing the acknowledgement delay of the selected TCP stream by twenty-five percent.

7. A non-transitory computer-readable medium having computer executable instructions stored thereon which, when executed by a computer, will cause the computer to:

determine whether at least one user data protocol (UDP) session comprising at least one UDP stream is active on a subscriber loop;

in response to the determination that the at least one UDP session is active on the subscriber loop, send a query to a bandwidth monitor, wherein the query requests a current total bandwidth usage, and a relative distribution of bandwidth usage among a plurality of Transport Control Protocol (TCP) steams carried on the subscriber loop;

receive a notification from the bandwidth monitor indicative that the current total bandwidth usage, and the relative distribution of bandwidth usage among the plurality of TCP streams on the subscriber loop has crossed a threshold;

compare the current total bandwidth usage with a predetermined threshold;

in response to the current bandwidth usage surpassing the predetermined threshold, select at least one of the plurality of TCP streams based on the relative distribution of the bandwidth carried on the subscriber loop, wherein the selected at least one of the TCP streams having the highest bandwidth usage among the plurality of TCP streams; and

reduce the bandwidth usage for the selected at least one of the plurality of TCP streams by adjusting at least one flow control parameter of the selected TCP stream based on the relative distribution of the bandwidth, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises adjusting at least one of;

a sliding window size and an acknowledgement delay.

8. The non-transitory computer readable medium of claim 7, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises decreasing the sliding window size of the selected TCP stream.

9. The non-transitory computer readable medium of claim 7, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises increasing the acknowledgement delay of the selected TCP stream.

17. The non-transitory computer readable medium of claim 7, wherein adjusting the at least one flow control parameter for the selected at least one of the plurality of TCP streams comprises terminating the selected at least one of the plurality of TCP streams.

18. The non-transitory computer readable medium of claim 7, wherein selecting at least one of the plurality of TCP streams comprises selecting the at least one of the TCP streams having the highest bandwidth usage.

19. The non-transitory computer readable medium of claim 7, further causing the computer to:

periodically query a broadband Media Access Control (MAC) layer instance in order to determine a number of bytes received by the broadband MAC layer instance on at least each of the plurality of TCP streams; and

compute the total current bandwidth in use on the subscriber loop based on the number of bytes received by the broadband MAC layer instance.