Method for sharing a transport connection across a multi-processor platform with limited inter-processor communications

• US 20060176904A1
• Filed: 02/07/2005
• Published: 08/10/2006
• Est. Priority Date: 02/07/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Bryant, Stewart Frederick, Lei, Peter, Stewart, Randall
• Granted Patent: US 7,535,916 B2
• Time in Patent Office: Days
• US Class Current: 370/467
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 69/26 Special purpose or proprietary protocols or architectures network applications for proprietary or special purpose networking environments H04L67/12

Abstract

A method is disclosed for sharing a transport connection in a host having two or more processors that exchange limited inter-processor communications. Ranges of transport sequence numbers are assigned to the processors of the host, and a range assigned to a particular processor does not overlap with any other range assigned to any other processor. An outbound message is sent over the transport connection from a processor of the host, where the message includes a transport sequence number selected from the range assigned to that processor. An inbound message is received at a designated processor of the host that is configured to receive all inbound messages sent to the host over the transport connection.

Claims

1. A method for sharing a transport connection in a host having two or more processors that exchange limited inter-processor communications, the method comprising the computer-implemented steps of:

assigning ranges of transport sequence numbers to the two or more processors, wherein a particular range assigned to a particular processor does not overlap with any other range that is assigned to any other processor;

sending, over the transport connection, an outbound message from a processor of the two or more processors, wherein the message includes a transport sequence number selected only from the range of transport sequence numbers assigned to the processor; and

receiving, over the transport connection, an inbound message at a designated processor, wherein the designated processor is configured to receive all inbound messages sent to the host.

2. A method as recited in claim 1, further comprising:

generating a set of assigned ranges of transport sequence numbers; and

assigning a new range of transport sequence numbers, which is not in the set of assigned ranges, to each of the two or more processors, wherein a particular new range assigned to a particular processor does not overlap with any other range that is assigned to any other processor.

3. A method as recited in claim 2, wherein the steps of generating a set of assigned ranges and assigning a new range of transport sequence numbers are performed in response to the expiration of a timer.

4. A method as recited in claim 2, wherein the steps of generating a set of assigned ranges and assigning a new range of transport sequence numbers are performed in response to a request from a particular processor that has used all its transport sequence numbers.

5. A method as recited in claim 2, wherein the step of generating a set of assigned ranges comprises polling each of the two or more processors to determine the ranges of transport sequence numbers that are assigned to them.

6. A method as recited in claim 2, wherein the step of generating a set of assigned ranges comprises checking a table in memory to determine the ranges of transport sequence numbers that have been assigned.

7. A method as recited in claim 1, further comprising the step of sending to a peer host a forward cumulative transport sequence number, wherein the peer host skips any missing messages including transport sequence numbers that are smaller than or equal to the forward cumulative transport sequence number.

8. A method as recited in claim 1, wherein the step of assigning a range of transport sequence numbers is performed by making use of an inter-processor communication mechanism.

9. A method as recited in claim 1, wherein the transport connection is a Datagram Congestion Control Protocol (DCCP) connection.

10. A method for sharing a Stream Control Transmission Protocol (SCTP) transport connection across a host having two or more processors that exchange limited inter-processor communications, the method comprising the computer-implemented steps of:

establishing an SCTP association between the host and a peer host, wherein a designated processor of the host is configured to receive all messages sent over the SCTP association;

assigning a range of transport sequence numbers to each of the two or more processors, wherein a particular range assigned to a particular processor does not overlap with any other range that has been assigned to any other processor; and

sending a message from a processor of the two or more processors to the peer host over the SCTP association, wherein the message includes a verification tag of the SCTP association and a transport sequence number selected from the range of transport sequence numbers assigned to the processor.

11. A method as recited in claim 10, further comprising:

generating a set of assigned ranges of transport sequence numbers;

assigning a new range of transport sequence numbers, which is not in the set of assigned ranges, to each of the two or more processors, wherein a particular new range assigned to a particular processor does not overlap with any other range that is assigned to any other processor;

sending a forward cumulative transport sequence number to the peer host over the SCTP association; and

at the peer host, skipping past any missing messages that include transport sequence numbers that are smaller than or equal to the forward cumulative transport sequence number.

12. A method as recited in claim 11, wherein the steps of generating a set of assigned ranges, assigning a new range of transport sequence numbers, and sending a forward cumulative transport sequence number are performed in response to the expiration of a timer.

13. A method as recited in claim 11, wherein the steps of generating a set of assigned ranges, assigning a new range of transport sequence numbers, and sending a forward cumulative transport sequence number are performed in response to a request from a particular processor that has used all its transport sequence numbers.

14. A method as recited in claim 11, wherein the steps of generating a set of assigned ranges, assigning a new range of transport sequence numbers, and sending a forward cumulative transport sequence number are performed in response to the peer host failing to acknowledge the receipt of a preset number of messages.

15. A method as recited in claim 11, wherein the steps of generating a set of assigned ranges, assigning a new range of transport sequence numbers, and sending a forward cumulative transport sequence number are performed in response to the peer host acknowledging the receipt of a preset number of messages.

16. A method as recited in claim 11, wherein the step of generating a set of assigned ranges comprises polling each of the two or more processors to determine the ranges of transport sequence numbers that have been assigned to them.

17. A method as recited in claim 11, wherein the step of generating a set of assigned ranges comprises checking a table in memory to determine the ranges of transport sequence numbers that have been assigned to the two or more processors.

18. A method as recited in claim 10, further comprising assigning a different stream of the SCTP association to each of the two or more processors, wherein each of the two or more processors sends messages only over the stream assigned to it.

19. A method as recited in claim 10, wherein:

the host comprises a router; and

the peer host comprises a collector that is configured to collect network management information.

20. A method as recited in claim 10, wherein the SCTP association is established according to a Partial Reliability Stream Control Transmission Protocol (PR-SCTP) standard.

21. An apparatus comprising:

a memory;

two or more processors operatively coupled to the memory, wherein;

the two or more processors exchange limited inter-processor communications; and

each of the two or more processors is operatively connected to a network; and

one or more stored sequences of instructions which, when executed by the two or more processors, cause the two or more processors to carry out the steps of;

assigning ranges of transport sequence numbers to the two or more processors, wherein a particular range assigned to a particular processor does not overlap with any other range that is assigned to any other processor;

sending, over the network, an outbound message from a processor of the two or more processors, wherein the message includes a transport sequence number selected only from the range of transport sequence numbers assigned to the processor; and

receiving, over the network, an inbound message at a designated processor, wherein the designated processor is configured to receive all inbound messages from the network.

22. An apparatus as recited in claim 21, wherein the apparatus comprises a router.

23. A computer-readable medium carrying one or more sequences of instructions for sharing a transport connection across a host having two or more processors that exchange limited inter-processor communications, which instructions, when executed by one or more processors, cause the one or more processors to carry out the steps of:

assigning ranges of transport sequence numbers to the two or more processors, wherein a particular range assigned to a particular processor does not overlap with any other range that is assigned to any other processor;

sending, over the transport connection, an outbound message from a processor of the two or more processors, wherein the message includes a transport sequence number selected only from the range of transport sequence numbers assigned to the processor; and

receiving, over the transport connection, an inbound message at a designated processor, wherein the designated processor is configured to receive all inbound messages sent to the host.

24. A computer-readable medium as recited in claim 23, further comprising instructions which, when executed by the one or more processors, cause the one or more processors to carry out the steps of:

generating a set of assigned ranges of transport sequence numbers; and

assigning a new range of transport sequence numbers, which is not in the set of assigned ranges, to each of the two or more processors, wherein a particular new range assigned to a particular processor does not overlap with any other range that is assigned to any other processor.

25. A computer-readable medium as recited in claim 23, further comprising instructions which, when executed by the one or more processors, cause the one or more processors to carry out the step of sending to a peer host a forward cumulative transport sequence number, wherein the peer host skips any missing messages including transport sequence numbers that are smaller than or equal to the forward cumulative transport sequence number.

26. A computer-readable medium as recited in claim 23, wherein the transport connection is a Datagram Congestion Control Protocol (DCCP) connection.

27. A computer-readable medium carrying one or more sequences of instructions for sharing a Stream Control Transmission Protocol (SCTP) transport connection across a host having two or more processors that exchange limited inter-processor communications, which instructions, when executed by one or more processors, cause the one or more processors to carry out the steps of:

establishing an SCTP association between the host and a peer host, wherein a designated processor of the host is configured to receive all messages sent over the SCTP association;

assigning a range of transport sequence numbers to each of the two or more processors, wherein a particular range assigned to a particular processor does not overlap with any other range that has been assigned to any other processor; and

sending a message from a processor of the two or more processors to the peer host over the SCTP association, wherein the message includes a verification tag of the SCTP association and a transport sequence number selected from the range of transport sequence numbers assigned to the processor.

28. A computer-readable medium as recited in claim 27, further comprising instructions which, when executed by the one or more processors, cause the one or more processors to carry out the steps of:

generating a set of assigned ranges of transport sequence numbers;

assigning a new range of transport sequence numbers, which is not in the set of assigned ranges, to each of the two or more processors, wherein a particular new range assigned to a particular processor does not overlap with any other range that is assigned to any other processor;

sending a forward cumulative transport sequence number to the peer host over the SCTP association; and

at the peer host, skipping past any missing messages that include transport sequence numbers that are smaller than or equal to the forward cumulative transport sequence number.

29. A computer-readable medium as recited in claim 28, wherein the instructions for carrying out the steps of generating a set of assigned ranges, assigning a new range of transport sequence numbers, and sending a forward cumulative transport sequence number further comprise instructions for carrying out the steps in response to a request from a particular processor that has used all its transport sequence numbers.

30. A computer-readable medium as recited in claim 28, wherein the instructions for carrying out the steps of generating a set of assigned ranges, assigning a new range of transport sequence numbers, and sending a forward cumulative transport sequence number further comprise instructions for carrying out the steps in response to the peer host acknowledging the receipt of a preset number of messages.

31. A computer-readable medium as recited in claim 27, further comprising instructions which, when executed by the one or more processors, cause the one or more processors to carry out the step of assigning a different stream of the SCTP association to each of the two or more processors, wherein each of the two or more processors sends messages only over the stream assigned to it.

32. A computer-readable medium as recited in claim 27, wherein the SCTP association is established according to a Partial Reliability Stream Control Transmission Protocol (PR-SCTP) standard.