Apparatus and system for coupling and decoupling initiator devices to a network using an arbitrated loop without disrupting the network

• US 7,796,627 B2
• Filed: 07/13/2005
• Issued: 09/14/2010
• Est. Priority Date: 08/12/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Ip, Alfonso Y., Hurley, Kean P., Saklecha, Bhavi
• Primary Examiner(s): Phunkulh; Bob A
• Application Number:
  US11/179,732
• Publication Number:
  US 20060034192A1
• Time in Patent Office: 1,889 Days
• Field of Search: None
• US Class Current: 370/419
• CPC Class Codes: H04L 41/046 comprising network management agents or mobile agents therefor
• CPC Class Codes: H04L 41/0806 for initial configuration or provisioning, e.g. plug-and-play
• CPC Class Codes: H04L 41/082 the condition being updates or upgrades of network functionality
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/357 Fibre channel switches

Abstract

The present invention enables the coupling and decoupling of multiple processing devices to a network without disrupting the network. In an embodiment, the invention provides a switch having a network port and several initiator ports each configured for coupling to a processing device. The switch is configured to route data from the network port to the initiator ports and from the initiator ports to the network port. A management agent facilitates operation of the switch by processing port initializations, replying to device registration requests, and processing predetermined unsolicited discovery commands. During operation, the management agent enables configuration changes caused, for example, by the coupling and/or decoupling of processing device to initiator ports.

Claims

1. An apparatus for coupling multiple processing devices to a network, comprising:

a switch that includes a network port configured to route frames based on a plurality of arbitrated loop physical addresses, the network port configured for coupling to a network, and one or more initiator ports each configured for coupling to one or more processing devices, wherein the switch routes data from the network port to the plurality of initiator ports and from the plurality of initiator ports to the network port; and

a management agent, wherein, during operation of the apparatus, the management agent enables configuration changes caused by the coupling of a first processing device to a first initiator port of the plurality of initiator ports or by the decoupling of the first processing device from the first initiator port by facilitating continued communications between a second processing device coupled to a second initiator port and a target device coupled to the network port, and wherein the management agent includes

a front-end for performing operations relating to tasks associated with the network port; and

a back-end for performing operations relating to tasks associated with the initiator ports.

2. The apparatus of claim 1, wherein the network port appears to a coupled target device as a Fibre Channel Standards NL_PORT.

3. The apparatus of claim 2, wherein the network port operates in one of an open primitive signal state and an open primitive signal full duplex state.

4. The apparatus of claim 2, wherein the network port sends data from multiple processing devices, coupled to the network port, within a single tenancy, wherein each of the multiple processing devices is associated with a different arbitrated loop physical address.

5. The apparatus of claim 2, wherein each initiator port appears to a coupled processing device as a Fibre Channel Standards F_PORT.

6. The apparatus of claim 2, wherein the switch includes a routing table that associates a network port arbitrated loop physical address with one of the plurality of initiator ports.

7. The apparatus of claim 2, wherein the switch routes Fibre Channel Extended Link Services commands to the management agent for processing.

8. The apparatus of claim 2, wherein the switch routes Fibre Channel Login data to the management agent for processing.

9. The apparatus of claim 1, wherein the management agent comprises firmware.

10. The apparatus of claim 1, wherein the front-end is configured to process one or more of:

network port initialization;

device registration with a network controller;

device registration with a name server;

exchange cleanup handling;

unsolicited ELS and fabric service frames sent from a fabric;

proxy agent probing;

unsolicited FCP-SCSI discovery commands;

SCSI inquiries; and

product data page information.

11. The apparatus of claim 1, wherein the back-end is configured to process one or more of:

initiator port initialization;

unsolicited ELS/fabric service frames required for FCP-SCSI initiators;

fabric control frame requests;

name server registrations; and

name server queries.

12. The apparatus of claim 1, wherein each processing device coupled to one of the plurality of initiator ports operates without knowledge of the management agent, as if each processing device were coupled directly to the network.

13. The apparatus of claim 1, wherein the management agent is configured to facilitate operation of the switch by processing port initializations, replying to device registration requests, and processing predetermined unsolicited discovery commands.

14. An apparatus for coupling multiple processing devices to a network, comprising:

a network port, configured for coupling to a network, configured to route frames based on a predetermined number of arbitrated loop physical addresses;

a plurality of initiator ports each configured for coupling to a processing device;

computer logic, coupled to the network port and the plurality of initiator ports; and

software, configured to be executed by the computer logic, wherein, during operation of the apparatus, the computer logic and the software enable configuration changes caused by the coupling of a first processing device to a first initiator port of the plurality of initiator ports or by the decoupling of the first processing device from the first initiator port by facilitating continued communications between a second processing device coupled to a second initiator port and a target device coupled to the network port, and wherein the software includes

a front-end portion for performing operations relating to tasks associated with the network port; and

a back-end portion for performing operations relating to tasks associated with the initiator ports.

15. The apparatus of claim 14, wherein the network port appears to a coupled target device as a Fibre Channel Standards NL_PORT.

16. The apparatus of claim 15, wherein the network port operates in one of an open primitive signal state and an open primitive signal full duplex state.

17. The apparatus of claim 15, wherein the network port sends data from multiple processing devices, coupled to the network port, within a single tenancy, wherein each of the multiple processing devices is associated with a different arbitrated loop physical address.

18. The apparatus of claim 15, wherein each initiator port appears to a coupled processing device as a Fibre Channel Standards F_PORT.

19. The apparatus of claim 15, wherein the computer logic and the software form a routing table that associates a network port arbitrated loop physical address with one of the plurality of initiator ports.

20. An apparatus for coupling multiple processing devices to a network, comprising:

a network port, configured for coupling to a network, configured to route frames based on a predetermined number of arbitrated loop physical addresses;

a plurality of initiator ports each configured for coupling to a processing device; and

processing means, coupled to the network port and the plurality of initiator ports, wherein during operation of the apparatus the processing means enables configuration changes caused by the coupling of a first processing device to a first initiator port of the plurality of initiator ports or by the decoupling of the first processing device from the first initiator port by facilitating continued communications between a second processing device coupled to a second initiator port and a target device coupled to the network port, the processing means including

front-end means for performing operations relating to tasks associated with the network port; and

back-end means for performing operations relating to tasks associated with the initiator ports.

21. The apparatus of claim 20, wherein the network port appears to a coupled target device as a Fibre Channel Standards NL_PORT.

22. The apparatus of claim 20, wherein the network port sends data from multiple processing devices, coupled to the network port, within a single tenancy, wherein each of the multiple processing devices is associated with a different arbitrated loop physical address.

23. The apparatus of claim 20, wherein each initiator port appears to a coupled processing device as a Fibre Channel Standards F_PORT.

24. The apparatus of claim 20, wherein the processing means includes a routing table that associates a network port arbitrated loop physical address with one of the plurality of initiator ports.

25. A system for coupling multiple processing devices to a network, comprising:

a plurality of initiator devices;

a plurality of network switches coupled by an inter-switch communications link, wherein each network switch includes a network port and an initiator port;

an aggregator circuit that couples the initiator devices to an external network, the aggregator circuit including the plurality of network switches; and

a management agent, wherein, during operation of the system, the management agent enables configuration changes caused by the coupling of a first processing device to a first initiator port of one of the plurality of network switches or by the decoupling of the first processing device from the first initiator port by facilitating continued communications between a second processing device coupled to a second initiator port of one of the plurality of network switches and a target device coupled to a first network port of one of the plurality of network switches, and wherein the management agent includes

a front-end for performing operations relating to tasks associated with the network port; and

a back-end for performing operations relating to tasks associated with the initiator port.