Optical safety and connections discovery

• US 10,397,091 B1
• Filed: 09/17/2018
• Issued: 08/27/2019
• Est. Priority Date: 09/17/2018
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Gumier, Luca, Piciaccia, Stefano, Brunella, Mauro
• Primary Examiner(s): Alagheband, Abbas H
• Application Number:
  US16/132,993
• Time in Patent Office: 344 Days
• Field of Search: 398141, 398 15, 398 17, 398 34, 398 94, 370535, 370470, 370512, 370410
• CPC Class Codes: H04B 10/0773 Network aspects, e.g. central monitoring of transmission parameters
• CPC Class Codes: H04B 10/0775 Performance monitoring and measurement of transmission parameters
• CPC Class Codes: H04B 10/079 using measurements of the data signal
• CPC Class Codes: H04J 14/0221 Power control, e.g. to keep the total optical power constant
• 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 14/0268 Restoration of optical paths, e.g. p-cycles
• CPC Class Codes: H04J 14/0275 using an optical service channel
• CPC Class Codes: H04J 14/0297 Optical equipment protection
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks

Abstract

At a first optical node of an optical communications system, during a signal initialization phase, a first optical pattern is received that includes a prefix indicating a beginning of a signal, a first word, and a first working signal for verifying stability of a connection between the first optical node and a second optical node of the optical communications system. A second optical pattern is transmitted that includes the prefix, a second word different from the first word, and the first working signal. A third optical pattern including the prefix, the first word, and a second working signal is received. Based on determining that a duration of the second working signal is greater than a duration of the first working signal plus a predetermined time, the first optical node determines that the second optical node is an adjacent node of the first optical node.

Claims

1. A method comprising:

at a first optical node of an optical communications system;

during a signal initialization phase, receiving a first optical pattern including a prefix indicating a beginning of a signal, a first word, and a first working signal for verifying stability of a connection between the first optical node and a second optical node of the optical communications system;

in response to the receiving, transmitting a second optical pattern including the prefix, a second word different from the first word, and the first working signal;

after transmitting the second optical pattern, receiving a third optical pattern including the prefix, the first word, and a second working signal for verifying stability of the connection between the first optical node and the second optical node;

determining if a duration of the second working signal is greater than a duration of the first working signal plus a predetermined time; and

based on determining that the duration of the second working signal is greater than the duration of the first working signal plus the predetermined time, determining that the second optical node is an adjacent node of the first optical node.

2. The method of claim 1, wherein the first word is indicative of a unique identifier of the second optical node.

3. The method of claim 2, wherein the second word is indicative of a unique identifier of the first optical node.

4. The method of claim 3, wherein the first word and the second word are Ethernet interface media access control addresses.

5. The method of claim 1, further comprising:

in response to determining that the duration of the second working signal is greater than the duration of the first working signal plus the predetermined time, transmitting a data modulated optical signal to the second optical node.

6. The method of claim 1, wherein the transmitting and the receiving are performed in a communication channel other than an optical service channel.

7. The method of claim 1, further comprising:

based on determining that the duration of the second working signal is not greater than the duration of the first working signal plus the predetermined time, transmitting the second optical pattern.

8. An apparatus, comprising:

an optical communication interface that enables optical network communications on behalf of a first optical node;

a processor; and

a memory to store data and instructions executable by the processor,

wherein the processor is coupled to the optical communication interface and to the memory, and is configured to execute the instructions to;

during a signal initialization phase, receive a first optical pattern including a prefix indicating a beginning of a signal, a first word, and a first working signal for verifying stability of a connection between the first optical node and a second optical node in an optical communications system;

in response to receiving the first optical pattern, transmit a second optical pattern including the prefix, a second word different from the first word, and the first working signal;

after transmitting the second optical pattern, receive a third optical pattern including the prefix, the first word, and a second working signal for verifying stability of the connection between the first optical node and the second optical node;

determine if a duration of the second working signal is greater than a duration of the first working signal plus a predetermined time; and

based on determining that the duration of the second working signal is greater than the duration of the first working signal plus the predetermined time, determine that the second optical node is an adjacent node of the first optical node.

9. The apparatus of claim 8, wherein the first word is indicative of a unique identifier of the second optical node.

10. The apparatus of claim 9, wherein the second word is indicative of a unique identifier of the first optical node.

11. The apparatus of claim 10, wherein the first word and the second word are Ethernet interface media access control addresses.

12. The apparatus of claim 8, wherein the processor is configured to execute the instructions to:

based on determining that the duration of the second working signal is greater than the duration of the first working signal plus the predetermined time, transmit a data modulated optical signal to the second optical node.

13. The apparatus of claim 8, wherein the processor is configured to transmit and receive the optical patterns in a communication channel other than an optical service channel.

14. The apparatus of claim 8, wherein the processor is configured to execute the instructions to:

based on determining that the duration of the second working signal is not greater than the duration of the first working signal plus the predetermined time, transmit the second optical pattern.

15. A non-transitory computer-readable storage medium encoded with software comprising computer executable instructions which, when executed by a processor of a first optical node of an optical communications system, cause the processor to:

during a signal initialization phase, receive a first optical pattern including a prefix indicating a beginning of a signal, a first word, and a first working signal for verifying stability of a connection between the first optical node and a second optical node of the optical communications system;

in response to receiving the first optical pattern, transmit a second optical pattern including the prefix, a second word different from the first word, and the first working signal;

after transmitting the second optical pattern, receive a third optical pattern including the prefix, the first word, and a second working signal for verifying stability of the connection between the first optical node and the second optical node;

determine if a duration of the second working signal is greater than a duration of the first working signal plus a predetermined time; and

based on determining that the duration of the second working signal is greater than the duration of the first working signal plus the predetermined time, determine that the second optical node is an adjacent node of the first optical node.

16. The non-transitory computer-readable storage medium of claim 15, wherein the first word is indicative of a unique identifier of the second optical node.

17. The non-transitory computer-readable storage medium of claim 16, wherein the second word is indicative of a unique identifier of the first optical node.

18. The non-transitory computer-readable storage medium of claim 17, wherein the first word and the second word are Ethernet interface media access control addresses.

19. The non-transitory computer-readable storage medium of claim 15, wherein the instructions further cause the processor to:

based on determining that the duration of the second working signal is greater than the duration of the first working signal plus the predetermined time, transmit a data modulated optical signal to the second optical node.

20. The non-transitory computer-readable storage medium of claim 15, wherein the instructions further cause the processor to:

based on determining that the duration of the second working signal is not greater than the duration of the first working signal plus the predetermined time, transmit the second optical pattern.