Arbitrated loop address management apparatus method and system

• US 7,782,845 B2
• Filed: 11/19/2004
• Issued: 08/24/2010
• Est. Priority Date: 11/19/2004
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Seidel, Andrew Ellis, Cagno, Brian James, Lucas, Gregg Steven, Qiu, Kenny Nian Gan, Bomhoff, Matthew David
• Primary Examiner(s): Kumar; Pankaj
• Assistant Examiner(s): Duong; Duc T
• Application Number:
  US10/993,554
• Publication Number:
  US 20060109844A1
• Time in Patent Office: 2,104 Days
• Field of Search: 370/389, 370/392, 370/397, 370/399, 370/401, 370/404, 370/409
• US Class Current: 370/389
• CPC Class Codes: H04L 12/42 Loop networks
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming

Abstract

An apparatus, system, and method are disclosed for automatically and transparently managing addresses in an arbitrated loop network. An arbitrated loop network switch is programmed with an address map and configured with the necessary modules to monitor an address assignment process and associate soft assigned addresses claimed during the address arbitration process with physical slot addresses. In one embodiment, the address fields of packets addressing a specific physical slot are changed (in route) to the soft address assigned during the address arbitration process. The entire process may be transparent to the rest of the network and to users. The present invention facilitates maintaining a physically ordered addressing scheme despite any soft addressing that occurs during loop initialization.

Claims

1. An apparatus for managing messaging in an arbitrated loop network, the apparatus comprising:

a memory device storing executable code;

a processor executing the executable code, the executable code comprising

an address map;

an address assignment monitor monitoring an address assignment process for a device in an arbitrated loop network and populating the address map to map an expected address for the device to an assigned address different from the expected address and claimed for the device in response to an error wherein the expected address and the assigned address are arbitrated loop network addresses; and

a switching array replacing the expected address with the assigned address in packets addressed to the device.

2. The apparatus of claim 1, wherein the expected address corresponds to a specific port of the switching array.

3. The apparatus of claim 2, the switching array further changing from a loop mode to a point-to-point mode.

4. The apparatus of claim 1, further comprising a memory storing the address map.

5. The apparatus of claim 4, wherein the memory is a non-volatile memory.

6. The apparatus of claim 1, wherein the device is a networked device operably connected to the switching array.

7. The apparatus of claim 6, wherein the networked device is a storage device.

8. The apparatus of claim 7, further comprising an enclosure enclosing the switching array and the networked device.

9. A method for managing messaging in an arbitrated loop network, the method comprising:

monitoring, by use of a processor, an address assignment process for a device in an arbitrated loop network;

populating an address map during the address assignment process to map an expected address for the device to an assigned address different from the expected address and claimed for the device in response to an error wherein the expected address and the assigned address are arbitrated loop network addresses; and

replacing the expected address with the assigned address in packets addressed to the device.

10. The method of claim 9, wherein the expected address corresponds to a specific port of a switching array.

11. The method of claim 9, further comprising changing the switching array from a loop mode to a point-to-point mode.

12. The method of claim 9, wherein routing packets in the arbitrated loop comprises point-to-point routing via the switching array.

13. The method of claim 9, further comprising changing a destination address field in the packets to the assigned address.

14. A system for managing messaging in an arbitrated loop network, the system comprising:

an arbitrated loop network; and

a switch monitoring an address assignment process for a device in the arbitrated loop network, updating an address map associated with the switch to map an expected address for the device to an assigned address different from the expected address and claimed for the device in response to an error wherein the expected address and the assigned address are arbitrated loop network addresses, and replacing the expected address with the assigned address in packets addressed to the device.

15. The system of claim 14, wherein the expected address corresponds to a specific port of the switch.

16. The system of claim 14, further comprising a plurality of networked devices.

17. The system of claim 16, wherein the plurality of networked devices comprise a plurality of storage devices.

18. The system of claim 16, further comprising an enclosure enclosing at least one networked device of the plurality of networked devices.

19. The system of claim 14, further comprising a host.

20. The system of claim 14, further comprising a host bus adapter.

21. A memory device tangibly storing executable code executed by a processor to perform a method managing messaging in an arbitrated loop network, the method comprising:

monitoring an address assignment process for a device in an arbitrated loop network;

populating an address map during the address assignment process to map an expected address for the device to an assigned address different from the expected address and claimed for the device in response to an error wherein the expected address and the assigned address are arbitrated loop network addresses; and

replacing the expected address with the assigned address in packets addressed to the device.

22. The memory device of claim 21, wherein the expected address corresponds to a specific port on a switching array.

23. The memory device of claim 21, wherein the method further comprises changing the switching array from a loop mode to a point-to-point mode.

24. The memory device of claim 21, wherein the packets in the arbitrated loop comprises point-to-point routing via the switching array.

25. An apparatus for managing messaging in an arbitrated loop network, the apparatus comprising:

a memory device storing executable code;

a processor executing the executable code, the executable code comprising

means for monitoring an address assignment process for a device in an arbitrated loop network;

means for populating an address map to map an expected address to an assigned address different from the expected address and claimed for the device in response to an error wherein the expected address and the assigned address are arbitrated loop network addresses; and

means for replacing the expected address with the assigned address in packets addressed to the device.