Method apparatus and computer program product for optical network restoration

• US 6,377,374 B1
• Filed: 11/16/1999
• Issued: 04/23/2002
• Est. Priority Date: 02/20/1998
• Status: Expired due to Term

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: MCI Communications Corporation (Verizon Communications Inc.)
• Inventors: Georgiou, George, Urimindi, Reddy, Iraschko, Rainer, Robinson, Andrew N., Davis, Gary B.
• Primary Examiner(s): PASCAL, LESLIE C
• Application Number:
  US09/441,527
• Time in Patent Office: 889 Days
• Field of Search: 359/110, 359/117, 359/128, 359/161, 359/139, 370/217-220, 370/225, 370/228
• US Class Current: 398/82
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0241 Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
• CPC Class Codes: H04J 14/0284 WDM mesh architectures
• CPC Class Codes: H04J 14/0295 Shared protection at the optical channel (1:1, n:m)
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0079 Operation or maintenance aspects
• CPC Class Codes: H04Q 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability

Abstract

An method, apparatus, and computer program product for restoring a failed system in an optical mesh network. A system includes a first light termination element (LTE) and a second LTE. A first node in the network includes an optical switching unit (OSU) coupled to the first (LTE) of the system. A second node in the network includes a second OSU coupled to the second (LTE) of the system. The first node is coupled to the second node by a path. Optical data traffic can be transmitted between the first node and the second node via the path. Upon detection of a failure of the system, the first OSU and second OSU are notified of the failure. A primary role is assigned to one of the first and second OSUs, and a secondary role is assigned to the other one of the first and second OSUs. A primary restoration plan is determined by the primary OSU. Information identifying the primary restoration plan is sent from the primary OSU for effecting the restoration path to restore the system.

Claims

1. In an optical communications network having a system including a first light termination element (LTE) and a second LTE, a first optical switching unit (OSU) coupled to the first LTE of the system, a second OSU coupled to the second LTE of the system, the first OSU coupled to the second OSU by a path, whereby optical data traffic can be transmitted between the first OSU and the second OSU via the path, a method for providing a restoration path between the first OSU and the second OSU upon detection of a failure of the system, comprising the steps of:

(a) notifying the first OSU and second OSU of the failure;

(b) assigning a primary role to one of the first and second OSUs, and assigning a secondary role to the other one of the rest and second OSUs;

(c) determining a primary restoration plan, said determining step comprising said primary OSU communicating with a central network management center to verify that a particular restoration path, for use in said primary restoration plan, is available and in good working status; and

(d) sending information identifying said primary restoration plan from the primary OSU for effecting the restoration path and restoring the system.

2. The method of claim 1, wherein step (c) further comprises the steps of:

(c1) determining a location within the path responsible for the failure of the system; and

(c2) determining said primary restoration plan based upon the result of step (c1).

3. The method of claim 1, wherein said primary restoration plan of step (c) is selected from a plurality of possible plans by said primary OSU based on a communication between said primary OSU and a central network management center.

4. The method of claim 1, wherein said information sent from said primary OSU in step (d) is sent to other OSUs in the optical communications network including said second OSU.

5. An apparatus for configuring a restoration path in an optical network, comprising:

a system including a first light termination element (LTE) and a second LTE;

a primary optical switching unit (OSU) optically coupled to said first LTE;

a secondary OSU optically coupled to said second LTE;

said primary OSU optically coupled to said secondary OSU via a path, wherein said primary OSU includes;

a primary notification module for receiving a notification of a failure of said system;

a primary restoration path determination module for determining a primary restoration plan in response to said primary notification module receiving said notification of a failure, wherein said primary OSU communicates with a central network management center to verify that a particular restoration path, for use in said primary restoration plan, is available and in good working status; and

a primary sending module for sending information identifying said primary restoration plan from said primary OSU to configure a restoration path between said primary OSU and said secondary OSU in order to restore said system.

6. The apparatus according to claim 5, wherein said secondary OSU comprises:

a secondary notification module for receiving a notification of a failure of said system;

a secondary restoration path determination module for determining a secondary restoration plan in response to said secondary notification module receiving said notification of a failure;

a secondary-hold-offtimer for measuring a predetermined amount of time; and

a secondary sending module for sending further information identifying said secondary restoration plan, when said secondary-hold-off timer expires prior to said secondary OSU receiving said information identifying said primary restoration plan from said primary sending module, to effect the restoration path between said primary OSU and said secondary OSU in order to restore said system.

7. In an optical network, a system including a first LTE and a second LTE, a primary optical switching unit (OSU) optically coupled to the first LTE, a secondary OSU optically coupled to the second LTE, and the primary OSU optically coupled to the secondary OSU via a path, the primary OSU comprising:

a primary notification module for receiving a notification of a failure of the system;

a primary restoration path determination module for determining a primary restoration plan in response to said primary notification module receiving said notification of the failure, wherein said primary OSU communicates with a central network management center to verify that a particular restoration path, for use in said primary restoration plan, is available and in good working status; and

a primary sending module for sending information identifying said primary restoration plan from the primary OSU in order to configure a restoration path between the primary OSU and the secondary OSU in order to restore the system.

8. A computer program product including a computer usable medium having computer program logic recorded therein, the computer program logic comprising:

a first computer readable program code means for enabling a computer, in response to a notification of an LTE system failure, to determine whether the computer has a primary or a secondary role in restoring the failed LTE system;

a second computer readable program code means for enabling the computer to determine a primary restoration plan when the computer has said primary role in restoring the failed LTE system; and

a third computer readable program code means for enabling the computer to send information identifying said primary restoration plan in order to effect a restoration path that restores the failed LTE system, when the computer has said primary role in restoring the failed LTE system, wherein the computer communicates with a central network management center to verify that a particular restoration path, for use in said primary restoration plan, is available and in good working status.