Communication system with priority data compression

• US 7,319,667 B1
• Filed: 11/15/2000
• Issued: 01/15/2008
• Est. Priority Date: 11/15/2000
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Biederman, Daniel
• Primary Examiner(s): Chan; Wing
• Assistant Examiner(s): Mais; Mark A.
• Application Number:
  US09/713,849
• Time in Patent Office: 2,617 Days
• Field of Search: 370/230.1, 370/237, 370/349, 370/351, 370/352, 370/401, 370/465, 370/466, 370/471, 370/476, 370/477, 370/230, 709/201, 709/203, 709/212, 709/213, 709216-219, 709/246, 709/247
• US Class Current: 370/231
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/11 Identifying congestion
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 47/38 by adapting coding or compression rate
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC

Abstract

A data compression system that dynamically adapts the degree of compression used in response to the priority of the data to be compressed is provided by virtue of one embodiment of the present invention. In one embodiment, only low priority data is compressed while high priority data is passed through to the network in uncompressed form. Also, the compression ratio can be varied depending on the priority of the data to allocate a larger portion of available bandwidth to higher priority traffic while imposing greater compression related delay on lower priority traffic.

Claims

1. In a communication network, a method for forwarding data across said network, said method comprising:

associating each of two or more priority levels with different compression levels, wherein said priority levels are assigned to data supporting both real time and non-realtime communications;

receiving data comprising packets, wherein at least some of the packets support real time and at least some of the packets support non-real time communications;

assigning one of said priority levels to said data, wherein said priority level is based on a delay tolerance of said data and data supporting real time communication has a higher priority level than data not supporting real time communication;

selecting a compression level for said data based on said priority level; and

sending said data through said network.

2. The method of claim 1 further comprising:

compressing said data only if said priority level is below a threshold.

3. The method of claim 1 further comprising:

compressing said data according to said priority level prior to sending said data through said network.

4. The method of claim 1 wherein determining said compression level comprises determining said compression level according to an inverse relationship between said compression level and said priority level so that high priority traffic is favored in allocating bandwidth.

5. The method of claim 1 further comprising:

determining a compression level for said data based on said priority level and network congestion; and

compressing said data according to said priority level prior to sending said data through said network.

6. The method of claim 5 wherein determining mid compression level comprises determining said compression level according to an inverse relationship between said compression level and said priority level so that high priority traffic is favored in allocating bandwidth.

7. The method of claim 1 further comprising;

setting a threshold priority level for compression eligibility based on network congestion; and

compressing said data only if said priority level is below said threshold.

8. The method of claim 1 wherein said priority level corresponds to a quality of service class.

9. The method of claim 1 wherein said data comprises a packet.

28. The method of claim 1 wherein said data compression comprises at least three different levels of compression corresponding to different priority levels.

29. The method of claim 1 wherein data having a low priority level assigned thereto has a higher compression level and a longer processing delay than data having a high priority assigned thereto.

10. In a digital communication network, a method for forwarding packets across said network, said method comprising:

associating each of two or more priority levels with different compression levels, wherein said priority levels are assigned to data supporting both real time and non-realtime communications;

providing a data compression system having a variable compression level;

inputting said packets to said data compression system while adjusting said variable compression level for individual ones of said packets responsive to said priority level of said packets, wherein said priority level is based on a delay tolerance of said packets and packets supporting real time communication have a higher priority level than packets not supporting real time communication; and

sending said packets as compressed through said network.

11. In a digital communication network, apparatus for forwarding data across said network, said apparatus comprising:

a compression switch that receives said data and assigns a compression level to said data responsive to a priority level of said data, wherein said priority level is based on a delay tolerance of said data and is assigned to data supporting both real time and non-real time communications;

a compression system that compresses said data according to said compression level; and

an output interface that forwards said data across said network as compressed by said compression system;

wherein each of two or more priority levels are associated with different compression levels.

12. The apparatus of claim 11 wherein said compression system assigns said compression level according to an inverse relationship between said compression level and said priority level so that high priority traffic is favored in allocating bandwidth.

13. The apparatus of claim 11 further comprising:

a network congestion estimator that estimates network congestion; and

wherein said compression switch assigns said compression level responsive to said network congestion.

14. The apparatus of claim 11 wherein said data comprises a packet.

15. The apparatus of claim 11 wherein said priority level corresponds to a quality of service class.

16. A computer-readable medium encoded with a computer program for forwarding data across a network, said program comprising:

code that associates each of two or mote priority levels with different compression levels, wherein said priority levels are assigned to data supporting both real time and non-realtime communications;

code that assigns said priority level to said data, wherein said priority level is based on a delay tolerance of said data and data supporting real time communication has a higher priority level than data not supporting real time communication;

code that selects a compression level for said data based on said priority level; and

code that sends said data through said network.

17. The program of claim 16 further comprising:

code that compresses the data only if said priority level is below a threshold.

18. The program of claim 16 further comprising:

code that determines a compression level for said data based on said priority level; and

code that compresses said data according to said priority level prior to sending said packet through said network.

19. The program of claim 18 wherein said code that determines said compression level comprises code that determines said compression level according to an inverse relationship between said compression level and said priority level so that high priority traffic is favored in allocating bandwidth.

20. The program of claim 16 further comprising:

code that determines a compression level for said data based on said priority level and network congestion; and

code that compresses said data according to said priority level prior to sending said data through said network.

21. The program of claim 20 wherein said code that determines said compression level comprises code that determines said compression level according to an inverse relationship between said compression level and said priority level so that high priority traffic is favored in allocating bandwidth.

22. The program of claim 16 further comprising;

code that selects a threshold priority level for compression eligibility based on network congestion; and

code that compresses said data only if said priority level is below said threshold.

23. The program of claim 16 wherein said data comprises a packet.

24. The program of claim 16 wherein said priority level corresponds to a quality of service class.

25. A computer-readable medium encoded with a computer program for forwarding packets across a network, said program comprising:

code that provides a data compression system having a variable compression level;

code that inputs said packets to said data compression system while adjusting said variable compression level for individual ones of said packets responsive to priority level of said packets, wherein said priority level is based on a delay tolerance of said packets and is assigned to data supporting both real time and non-real time communications; and

code that sends said packets as compressed through said network;

wherein each of two or more priority levels are associated with different compression levels.

26. In a data communication network, apparatus for forwarding data across said network, said apparatus comprising:

means for associating each of two or more priority levels with different compression levels, wherein said priority levels are assigned to data supporting both real time and non-realtime communications;

means for assigning a priority level to said data wherein said priority level is based on a delay tolerance of said data and data supporting real time communication has a higher priority level than data not supporting real time communication;

means for selecting said data for data compression responsive to said priority level; and

means for sending said data through said network.

27. In a packet switched network, apparatus for forwarding packets across said network, said apparatus comprising:

means for compressing data using a variable compression level;

means for inputting said packets to said compressing means while adjusting said variable compression level for individual ones of said packets responsive to priority level of said packets, wherein said priority level is based on a delay tolerance of said packets and is assigned to data supporting both real time and non-real time communications; and

means for sending said packets as compressed through said network;

wherein each of two or more priority levels are associated with different compression levels.