Method and apparatus for network synchronization

• US 5,734,642 A
• Filed: 12/22/1995
• Issued: 03/31/1998
• Est. Priority Date: 12/22/1995
• Status: Expired due to Term

• Current Assignee: Computer Associates Think Inc. (Broadcom, Inc.)
• Original Assignee: Cabletron Systems Incorporated (Extreme Networks, Inc.)
• Inventors: Kenny, Patrick R., Rydeen, Michael J., Vaishnavi, Vick
• Primary Examiner(s): Kizou, Hassan
• Application Number:
  US08/577,429
• Time in Patent Office: 830 Days
• Field of Search: 370/252, 370/254, 370/255, 370/346, 370/449, 370/241, 340/825.06, 340/825.08, 340/825.54, 359/200.02
• US Class Current: 370/255
• CPC Class Codes: H04L 41/0213 Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks

Abstract

According to several aspects of the present invention, a network is monitored for status information indicative of the status of a manageable device within the network. A network manager receives the status information, and updates or initializes a device model in accordance with the status information. A state machine may be used to determine a new state for the device model, and to enable or disable the device model. The network manager may also take action to inquire as to the status of the manageable device, for example by polling the manageable device or by initiating a discovery process. The device model may be used by the network manager as a basis by which to control the manageable device, and thus control aspects of the communications within the network.

Claims

1. A method for determining a status of a device in a communications network, comprising the steps of:

receiving a status report, including information regarding the device;

determining a previous state of the device; and

maintaining a model of the device based upon a combination of the previous state of the device and the information regarding the device, wherein the step of maintaining includes setting a state of the model of the device to one of a predetermined plurality of states, the predetermined plurality of states including an established after lost state indicative that a successful discovery has not yet been performed with respect to the device.

2. The method of claim 1, further comprising the step of querying the device to provide additional information, and wherein the step of maintaining includes maintaining the model of the device based upon a combination of the previous state of the device, the information regarding the device, and the additional information.

3. The method of claim 1, wherein the step of receiving the status report includes receiving a message indicative of a hard reboot of the device.

4. The method of claim 1, wherein the step of receiving the status report includes receiving results of a discovery process performed on the communications network.

5. The method of claim 4 further comprising the step of initiating the discovery process in response to a state of the model of the device.

6. The method of claim 1, wherein the step of receiving the status report includes receiving results of a polling process.

7. The method of claim 1, further comprising the step of initiating the polling process in response to a state of the model of the device.

8. The method of claim 1, further comprising the step of providing a reset command to the device in response to a state of the model of the device.

9. The method of claim 1, wherein the step of maintaining includes enabling the model to indicate that the device is ready to be controlled by a network manager.

10. The method of claim 1 wherein the step of maintaining includes disabling the model to indicate that the device is not ready to be controlled by a network manager.

11. The method of claim 1, wherein the predetermined plurality of states further includes:

an unknown state indicative that there is insufficient information to determine a capability of the device;

an initialized state indicative that the device has been discovered and is ready to be controlled by a network manager; and

a lost state indicative that the device was previously ready to be controlled but did not respond to a status inquiry.

12. The method of claim 1, wherein the step of maintaining includes the steps of:

providing the previous state of the device and the information regarding the device to a state machine;

receiving an output of the state machine, the output being responsive to the previous state of the device and the information regarding the device; and

maintaining the model in accordance with the output of the state machine.

13. An apparatus for determining a status of a device in a communications network, the apparatus comprising:

means for receiving a status report, including information regarding the device;

means for determining a previous state of the device; and

means for maintaining a model of the device based upon a combination of the previous state of the device and the information regarding the device, wherein the means for maintaining includes means for setting a state of the model of the device to one of a predetermined plurality of states, the predetermined plurality of states including an established after lost state indicative that a successful discovery has not vet been performed with respect to the device.

14. The apparatus of claim 13 further comprising means for querying the device to provide additional information, and wherein the means for maintaining includes means for maintaining the model of the device based upon a combination of the previous state of the device, the information regarding the device, and the additional information.

15. The apparatus of claim 13, wherein the status report includes a message indicative of a hard reboot of the device.

16. The apparatus of claim 13, wherein the status report includes results of a discovery process performed on the communications network.

17. The apparatus of claim 16, further comprising means for initiating the discovery process in response to a state of the model of the device.

18. The apparatus of claim 13, wherein the status report includes results of a polling process.

19. The apparatus of claim 18, further comprising means for initiating the polling process in response to a state of the model of the device.

20. The apparatus of claim 13, further comprising means for providing a reset command to the device in response to a state of the model of the device.

21. The apparatus of claim 13, wherein the means for maintaining includes means for enabling the model to indicate that the device is ready to be controlled by a network manager.

22. The apparatus of claim 13, wherein the means for maintaining includes means for disabling the model to indicate that the device is not ready to be controlled by a network manager.

23. The apparatus of claim 13, wherein the predetermined plurality of states further includes:

an unknown state indicative that there is insufficient information to determine a capability of the device;

an initialized state indicative that the device has been discovered and is ready to be controlled by a network manager; and

a lost state indicative that the device was previously ready to be controlled but did not respond to a status inquiry.

24. The apparatus of claim 13, wherein the means for maintaining includes:

means for providing the previous state of the device and the information regarding the device to a state machine;

means for receiving an output of the state machine, the output being responsive to the previous state of the device and the information regarding the device; and

means for maintaining the model in accordance with the output of the state machine.

25. An apparatus for determining a status of a device in a communications network, the apparatus comprising:

a model of the device containing information regarding a previous state of the device;

a model control module coupled to the model of the device, the model control module having an input that receives a status report including information regarding the device, and an output that maintains the model of the device based upon a combination of the previous state of the device and the information regarding the device, wherein the output of the model control module sets a state of the model of the device to one of a predetermined plurality of states, the predetermined plurality of states including an established after lost state indicative that a successful discovery has not yet been performed with respect to the device.

26. The apparatus of claim 25, further comprising a mechanism, coupled to the model control module, the mechanism providing a query to the device so that the device provides additional information, the model control module maintaining the model of the device based upon a combination of the previous state of the device, the information regarding the device, and the additional information.

27. The apparatus of claim 25, wherein the status report includes a message indicative of a hard reboot of the device.

28. The apparatus of claim 25, wherein the status report includes results of a discovery process performed on the communications network.

29. The apparatus of claim 28, further comprising a discovery mechanism, coupled to the model control module and the communications network, the discovery mechanism being responsive to the model control module to invoke a discovery process on the communications network.

30. The apparatus of claim 25, wherein the status report includes results of a polling process.

31. The apparatus of claim 30, further comprising a polling manager coupled to the model control module and the communications network, the polling manager being responsive to the model control module to initiate the polling process on the device.

32. The apparatus of claim 25, further comprising a reset mechanism, coupled to the model control module and the communications network, the reset mechanism being responsive to the model control module to command a reset of the device.

33. The apparatus of claim 25, wherein the output of the model control module enables the model to indicate that the device is ready to be controlled by a network manager.

34. The apparatus of claim 25, wherein the output of the model control module disables the model to indicate that the device is not ready to be controlled by a network manager.

35. The apparatus of claim 25, wherein the predetermined plurality of states further includes:

an unknown state indicative that there is insufficient information to determine a capability of the device;

an initialized state indicative that the device has been discovered and is ready to be controlled by a network manager; and

a lost state indicative that the device was previously ready to be controlled but did not respond to a status inquiry.

36. The apparatus of claim 25, wherein the means for maintaining includes a state machine coupled to the model control module and the model of the device, the state machine having a first input that receives the previous state of the device, a second input that receives the information regarding the device to a state machine, and an output that provides information based upon which the model control module maintains the model.