Method and apparatus for supporting header suppression and multiple microflows in a network

• US 6,438,123 B1
• Filed: 01/04/1999
• Issued: 08/20/2002
• Est. Priority Date: 11/10/1998
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Chapman, John T.
• Primary Examiner(s): VINCENT, DAVID ROBERT
• Application Number:
  US09/225,894
• Time in Patent Office: 1,324 Days
• Field of Search: 370/260, 370/282, 370/352, 370/389, 370/351, 370/355, 370/356, 370/400, 370/428, 370/458, 370/469-477, 725/111, 725/135, 725/138, 725/139-142, 725/143-151, 375/222
• US Class Current: 370/351
• 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 69/14 Multichannel or multilink protocols
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A first packet processing node in a header suppression mode suppresses transmission of one or more packet headers. A second packet processing node receives the packets from the first packet processing node over a network medium and sends the received packets to an endpoint. The second packet processing node includes a memory that contains the packet headers suppressed by the first packet processing node and appends the stored headers to the suppressed packets before sending the packets to the endpoint. Cable modems (CMs) include one or more Service Identifiers (SIDs) for establishing communication channels (microflows) with a Cable Modem Termination System (CMTS) through a cable medium. In another aspect of the intention, a cable modem network protocol is used between the CMTS and the CM to dynamically establish and modify multiple microflows between the CMTS and CM on the same cable modem SID.

Claims

1. A header suppression system, comprising:

a first packet processing node transmitting packets having multiple packet headers and a packet payload, the first packet processing node operating in a header suppression mode that suppresses transmission of one or more of the packet headers; and

a second packet processing node receiving the packets from the first packet processing node over a network medium and sending the received packets to an endpoint, the second packet processing node including a memory containing the packet headers suppressed by the first packet processing node and during the suppression mode appending the stored headers to the packets received from the first packet processing node before sending the packets to the endpoint.

2. A system according to claim 1 wherein one of the first or second packet processing nodes comprise a cable modem, the other packet processing node comprises a cable modem termination system and the network medium comprises a cable medium.

3. A system according to claim 1 including a protocol transmitting a header suppression notice, sending information identifying the suppressed headers, and initiating suppression of the identified headers in subsequently transmitted packets.

4. A system according to claim 3 wherein the protocol operates according to a Data Over Cable System Interface Specification (DOCSIS).

5. A system according to claim 1 including an index transmitted with the suppressed header packets, the index identifying the packets with a specific flow between the first and second packet processing nodes.

6. A system according to claim 5 wherein the index is located in an overhead field of the suppressed header packets.

7. A system according to claim 5 wherein the index is used by one of the first and second packet processing nodes to identify a memory location storing the suppressed headers associated with the suppressed header packets.

8. A system according to claim 1 wherein the suppressed headers include at least one of the following:

an Ethernet header;

an IP header;

or

an UDP header.

9. A system according to claim 2 wherein the cable modem termination system and the cable modem exchange Dynamic Service Change transmissions that establish multiple microflows for a common cable modem Service Identifier (SID) field.

10. A system according to claim 9 wherein the multiple microflows each carry a different phone call.

11. A system according to claim 9 wherein the multiple microflows each transmit audio packets according to allocated grants, the cable modem concatenating the audio packets for the microflows on the same SID together and transmitting the concatenated audio packets during the same grants.

12. A method for transmitting packets having multiple packet headers and a packet payload, comprising:

identifying one or more of the packet headers for header suppression;

pre-sending information from the identified packet headers to a packet processing node;

suppressing transmission of the identified packet headers when transmitting the packets to the packet processing node; and

providing an index with the suppressed header packets that enables the packet processing node to locate and append the pre-sent packet header information to the suppressed header packets.

13. A packet processing device that transmits packets having packet headers and a packet payload, the packet processing device:

identifying at least one of the packet headers for header suppression;

pre-sending packet header information from the identified packet headers to another packet processing device;

suppressing transmission of the identified packet headers when transmitting the packets to the other packet processing device; and

providing an index with the suppressed header packets that associates the pre-sent packet header information with the suppressed header packets.

17. A packet processing device according to claim 13 wherein the packet processing device comprises a cable modem or a cable modem termination system.

18. A packet processing device according to claim 17 including a cable modem protocol used by the cable modem or a cable modem termination system to transmit a header suppression notice and send information identifying the packet header information.

19. A packet processing device according to claim 13 wherein the index is located in an unsuppressed header transmitted with the packets.

20. A system according to claim 13 wherein the suppressed headers include at least one of the following:

an Ethernet header;

an IP header;

or

an UDP header.

14. A method for processing packets having multiple packet headers and a packet payload, comprising:

receiving one or more packets from a packet processing node identified for packet header suppression;

storing the additional packet headers for the identified packets;

receiving packets from the packet processing node identified as having suppressed packet headers;

appending the stored packet headers to the identified additional packets; and

forwarding the additional packets to an endpoint according to the appended packet headers.

15. A packet processing device for processing packets having multiple packet headers and a packet payload, the packet processing device:

receiving one or more packet headers from a packet processing node;

storing the packet headers;

receiving packets from the packet processing node having suppressed packet headers;

receiving an index that identifies the stored packet headers with the received packets;

appending the identified packet headers to the received packets; and

forwarding the packets to an endpoint according to the appended packet headers.

21. A packet processing device according to claim 15 wherein the packet processing device comprises a cable modem or a cable modem termination system.

22. A packet processing device according to claim 21 including a cable modem protocol used by the packet processing device to receive or send a header suppression notice and information identifying the suppressed header packets.

23. A packet processing device according to claim 15 wherein the index is appended to the received packets.

24. A system according to claim 15 wherein the packet headers include at least one of the following:

an Ethernet header;

an IP header;

or

an UDP header.

16. A method for transmitting packets having multiple packet headers and a packet payload, comprising:

identifying one or more of the packet headers for header suppression;

pre-sending information from the identified packet headers to a packet processing node;

suppressing transmission of the identified packet headers when transmitting the packets to the packet processing node; and

providing an identifier with the suppressed header packets that associates the pre-sent packet header information with the suppressed header packets.