Method, system, and computer program product for suppression index reuse and packet classification for payload header suppression

• US 20030014764A1
• Filed: 07/11/2002
• Published: 01/16/2003
• Est. Priority Date: 07/11/2001
• Status: Active Grant

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Robinson, Michael R., Gardner, Rennie L., Saladino, Anthony P., Gummalla, Ajay Chandra V.
• Granted Patent: US 7,688,824 B2
• Time in Patent Office: Days
• US Class Current: 725/111
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A cable modem method, system, and computer program product are provided for payload header suppression in which a limited number of suppression indices is used to map suppression rules to data streams. Network resources are conserved by implementing precise classification algorithms to correctly identify incoming packets at the cable modem as belonging to a particular data stream, which ensures that a minimum number of suppression indices are utilized. Additionally, network resources are conserved by utilizing sophisticated algorithms for reusing suppression indices when new data streams are detected by the cable modem. One such reuse algorithm involves recycling the suppression index that has been least recently used in transmitting a packet with a suppressed payload header.

Claims

1. A method for suppressing payload headers of a data stream based on a particular flow within a cable modem system, comprising the steps of:

detecting an incoming data stream;

identifying the incoming data stream as corresponding to a particular flow;

accessing a plurality of suppression indices; and

reusing one of the plurality of suppression/indices to produce a reused suppression index in response to determining no suppression index within the plurality of suppression indices being assigned to the particular flow,

wherein said reusing includes applying the reused suppression index to suppress a payload header corresponding to the incoming data stream.

2. The method according to claim 1, wherein said reusing step further comprises the step of:

sharing the reused suppression index with its currently assigned flow.

3. The method according to claim 1, wherein said reusing step further comprises the step of:

disassociating the reused suppression index from its currently assigned flow.

4. The method according to claim 1, wherein said reusing step further comprises the step of:

reusing a least recently used suppression index to produce the reused suppression index.

5. The method according to claim 4, wherein said reusing step further comprises the step of:

accessing a timestamp to select the least recently used suppression index.

6. The method according to claim 4, wherein said reusing step further comprises the step of:

accessing an ordered list to select the least recently used suppression index.

7. The method according to claim 1, wherein said reusing step further comprises the steps of:

monitoring the flows within the cable modem system to detect an inactive suppression index from the plurality of suppression indices; and

reusing the inactive suppression index to produce the reused suppression index.

8. The method according to claim 1, wherein said reusing step further comprises the steps of:

comparing a payload header corresponding to the incoming data stream with each payload header corresponding to a respective data stream having an assigned suppression index;

determining a similar payload header in response to said comparing step; and

applying the suppression index assigned to the similar payload header to produce the reused suppression index.

9. The method according to claim 1, wherein said reusing step further comprises the step of:

reusing a least often used suppression index to produce the reused suppression index.

10. The method according to claim 1, wherein said reusing step further comprises the steps of:

identifying more than one least recently used suppression index; and

reusing a least often used suppression index to produce the reused suppression index.

11. The method according to claim 1, wherein said reusing step further comprises the steps of:

identifying more than one least often used suppression index; and

reusing a least recently used suppression index to produce the reused suppression index.

13. The method according to claim 12, wherein said index reuse algorithm selects the suppression index that has been least recently used for transmitting a suppressed data packet.

14. The method according to claim 12, wherein said index reuse algorithm selects the suppression index that has been least often used for transmitting a suppressed data packet.

16. The system of claim 15, wherein said reusing means comprises:

selecting means for selecting a least recently used suppression index to produce said reused suppression index.

17. The system of claim 15, wherein said reusing means comprises:

selecting means for selecting a least often used suppression index to produce said reused suppression index.

18. The system of claim 15, wherein said reusing means comprises:

comparing means for comparing a payload header corresponding to said incoming data stream with each payload header corresponding to a respective data stream having an assigned suppression index; and

selecting means for selecting the most similar payload header among the compared payload headers, wherein the suppression index assigned to said similar payload header is applied to produce said reused suppression index.

20. The computer program product according to claim 19, wherein said third computer readable program code means comprises:

fourth computer readable program code means for selecting a least recently used suppression index to produce said reused suppression index.

21. The computer program product according to claim 19, wherein said third computer readable program code means comprises:

fourth computer readable program code means for selecting a least often used suppression index to produce said reused suppression index.

22. The computer program product according to claim 19, wherein said third computer readable program code means comprises:

fourth computer readable program code means for comparing a payload header corresponding to said incoming data stream with each payload header corresponding to a respective data stream having an assigned suppression index; and

fifth computer readable program code means for selecting the most similar payload header among the compared payload headers, wherein the suppression index assigned to said similar payload header is applied to produce said reused suppression index.

12. A method for assigning a suppression index to a packet stream in a cable modem system, wherein the suppression index is one of a limited number of suppression indices used for transmitting suppressed packets, comprising the steps of:

identifying a data stream; and

selecting a suppression index for assignment to said data stream from the limited number of suppression indices, wherein said selecting step comprises selecting said suppression index intelligently using an index reuse algorithm when all of said suppression indices have already been assigned to a data stream.

15. A system for reusing payload header suppression indices, comprising:

determining means for determining whether each suppression index within a plurality of suppression indices has been assigned to a data stream;

detecting means for detecting an incoming data stream having no assigned suppression index; and

reusing means for intelligently selecting one of said plurality of suppression indices to produce a reused suppression index, wherein said reused suppression index is assigned to said incoming data stream.

19. A computer program product comprising a computer useable medium having computer readable program code means embedded in said medium for causing an application program to execute on a computer that reuses payload header suppression indices, comprising:

first computer readable program code means for causing the computer to determine whether each suppression index within a plurality of suppression indices has been assigned to a data stream;

second computer readable program code means for causing the computer to detect an incoming data stream having no assigned suppression index; and

third computer readable program code means for causing the computer to intelligently select one of said plurality of suppression indices to produce a reused suppression index, wherein said reused suppression index is assigned to said incoming data stream.