Signal processing allocation using credit prediction

• US 7,583,658 B1
• Filed: 06/17/2004
• Issued: 09/01/2009
• Est. Priority Date: 06/17/2004
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Miriyala, Prasad, Wang, Jianxin
• Primary Examiner(s): NGUYEN, STEVEN H D
• Application Number:
  US10/871,581
• Time in Patent Office: 1,902 Days
• Field of Search: None
• US Class Current: 370/352
• CPC Class Codes: G10L 19/22 Mode decision, i.e. based on audio signal content versus external parameters

Abstract

Digital signal processing resource allocation using a credit prediction scheme is described. The digital signal processing allocation method may include predicting a digital signal processor (DSP) codec that could be requested by a channel at a channel setup stage when a requested codec is unknown; and selecting a DSP having the codec from among a plurality of DSPs to open the channel based on the predicting.

Claims

1. A method, comprising:

predicting a number of credits of a signal processor for a channel at a channel setup stage when a codec is unknown to determine the codec, wherein the predicting comprises

preallocating a total number of credits for each of a plurality of signal processors; and

calculating a potential credit growth against the total number of credits available for a currently considered signal processor; and

selecting, by a processing device, a signal processor having the codec from among the plurality of signal processors to open the channel based on the predicting.

2. The method of claim 1, wherein predicting further comprises:

determining whether the currently considered signal processor will not run short of credits if all opened channels use a highest complexity codec.

3. The method of claim 2, wherein predicting further comprises performing at least one of:

determining whether the currently considered signal processor does not have a potential for running out of credits when all the preallocated total number of credits for the plurality of signal processors can handle the highest complexity codec; and

determining a load balance for the plurality of signal processors.

4. The method of claim 2, wherein determining whether the currently considered signal processor will not run short of credits if all opened channels use a highest complexity codec comprises:

determining whether the total number of credits for the currently considered signal processor is greater than or equal to a maximum number of credits for a requested channel and, if so, selecting the currently considered signal processor for the requested channel.

5. The method of claim 3, wherein determining whether the currently considered signal processor does not have a potential for running out of credits when all the preallocated total number of credits for the plurality of signal processors can handle the highest complexity codec comprises:

assuming n number of channels open on the currently considered signal processor, among which m number of channels are have an unknown codec and n-m number of channels have a known codec;

determining a total number of available credits based on an actual credit usage by all open channels;

determining whether an available number of credits for the currently considered signal processor is greater than or equal to a maximum number of credits per channel minus a minimum number of credits per channel, multiplied by the m number of channels having the unknown codec plus the maximum number of credits per channel; and

if so, selecting the currently considered signal processor for the requested channel.

6. The method of claim 3, wherein determining a load balance for the plurality of signal processors comprises:

selecting a signal processor of the plurality of signal processors that has sufficient bandwidth to open the requested channel assuming that a new channel to be opened and any open but unestablished channels on the signal processor require more than a minimum amount of bandwidth per channel.

7. The method of claim 6, wherein determining a load balance for the plurality of signal processors further comprises:

determining whether an amount of available bandwidth in a first signal processor having a maximum amount of available bandwidth is sufficient to meet the bandwidth requirements of the new channel assuming that the new channel and any open but unestablished channels on the first signal processor will require a maximum amount of bandwidth per channel when established; and

selecting the first signal processor if the amount of available bandwidth is sufficient.

8. The method of claim 7, wherein selecting the signal processor further comprises:

if the amount of available bandwidth of the first signal processor is not sufficient, then determining whether an amount of available bandwidth in a second signal processor is sufficient to meet the bandwidth requirements of the new channel assuming that the new channel and any open but unestablished channels on the second signal processor will require a maximum amount of bandwidth per channel when established; and

selecting the second signal processor if the amount of available bandwidth in the second signal processor is sufficient.

9. The method of claim 8, wherein selecting the signal processor further comprises:

if the amount of available bandwidth in the second signal processor is not sufficient, then determining an amount of spare bandwidth in the plurality of signal processors; and

selecting the signal processor with the greatest amount of spare bandwidth.

10. The method of claim 1, wherein each of the plurality of signal processors is a digital signal processor.

11. An apparatus, comprising:

a plurality of signal processors, each having at least one codec; and

a processing device coupled to the plurality of signal processors, the processing device configured to predict a number of credits of the signal processors for a channel at a channel setup stage when a codec is unknown to determine the codec and selecting a signal processor of the plurality of signal processors having the codec to open the channel based on the prediction, and a credit table including a maximum number of channels per signal processor and credits required per channel for each of the at least one codec.

12. The apparatus of claim 11, further comprising signal processor firmware comprising credit table information.

13. The apparatus of claim 11, further comprising an Internetwork Operating System (IOS) code wherein the IOS code comprises the credit table.

14. The apparatus of claim 13, wherein the processing device is further configured to preallocate a total number of credits for each of the plurality of signal processors and calculate a potential credit growth against the total number of credits available for a currently considered signal processor.

15. The apparatus of claim 14, wherein the processing device is further configured to determine whether the currently considered signal processor will not run short of credits if all opened channels use a highest complexity codec.

16. The apparatus of claim 14, wherein the processing device is further configured to perform at least one of:

determining whether the currently considered signal processor does not have a potential for running out of credits when all the preallocated total number of credits for the plurality of signal processors can handle the highest complexity codec; and

determining a load balance for the plurality of signal processors.

17. The apparatus of claim 11, wherein each of the plurality of signal processors is a digital signal processor.

18. An apparatus, comprising:

means for predicting a number of credits of a signal processor that for a channel at a channel setup stage when a codec is unknown to determine the codec;

means for selecting a signal processor having the codec from among a plurality of signal processors to open the channel based on the predicting; and

means for preallocating a total number of credits for each of the plurality of signal processors and calculating a potential credit growth against the total number of credits available for a currently considered signal processor.

19. The apparatus of claim 18, wherein the means for predicting further comprises means for determining whether the currently considered signal processor will not run short of credits if all opened channels use a highest complexity codec.

20. The apparatus of claim 19, wherein the means for predicting further comprises means for performing at least one of determining whether the currently considered signal processor does not have a potential for running out of credits when all the preallocated total number of credits for the plurality of signal processors can handle the highest complexity codec, and determining a load balance for the plurality of signal processors.

21. The apparatus of claim 18, wherein each of the plurality of signal processors is a digital signal processor.

22. A machine accessible storage medium that stores instructions which, when executed by a processing device, cause the processing device to perform operations comprising:

predicting a number of credits of a signal processor for a channel at a channel setup stage when a codec is unknown to determine the codec wherein the predicting comprises

preallocating a total number of credits for each of a plurality of signal processors; and

calculating a potential credit growth against the total number of credits available for a currently considered signal processor; and

selecting a signal processor having the codec from among the plurality of signal processors to open the channel based on the predicting.

23. The machine accessible storage medium of claim 22, wherein predicting further comprises determining whether the currently considered signal processor will not run short of credits if all opened channels use a highest complexity codec.

24. The machine accessible storage medium of claim 23, wherein predicting further comprises performing at least one of:

determining whether the currently considered signal processor does not have a potential for running out of credits when all the preallocated total number of credits for the plurality of signal processors can handle the highest complexity codec; and

determining a load balance for the plurality of signal processors.