SONET Jo byte message monitoring system

• US 6,278,535 B1
• Filed: 05/06/1998
• Issued: 08/21/2001
• Est. Priority Date: 05/06/1998
• Status: Expired due to Term

• Current Assignee: Ciena Corporation
• Original Assignee: Ciena Corporation
• Inventors: Shanton, John L. III
• Primary Examiner(s): Pascal, Leslie
• Assistant Examiner(s): SEDIGHIAN, REZA
• Application Number:
  US09/072,780
• Time in Patent Office: 1,203 Days
• Field of Search: 370/474, 370/476, 370/428, 370/412, 370/429, 370/252, 359/124, 359/127, 359/155, 359/177, 375/224, 375/228
• US Class Current: 398/9
• CPC Class Codes: H04B 10/0771 Fault location on the transmission path
• CPC Class Codes: H04B 10/0775 Performance monitoring and measurement of transmission parameters
• CPC Class Codes: H04B 2210/071 using alarms
• CPC Class Codes: H04B 2210/072 using an overhead signal
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 2203/006 Fault tolerance and recovery
• CPC Class Codes: H04J 2203/0089 Multiplexing, e.g. coding, scrambling, SONET
• CPC Class Codes: H04J 3/085 for ring networks, e.g. SDH/SONET rings, self-healing rings, meashed SDH/SONET networks
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085

Abstract

A WDM system carrying a plurality of optical signals, each at a respective wavelength, is provided whereby each optical signal includes a plurality of frames, each frame conforming to a synchronous optical network (SONET) standard. A plurality of optical transmitter modules output a corresponding one of the plurality of optical signals, and each of a plurality of optical selector at a receiving end of the WDM system selects a respective one of the plurality of optical signals. In addition, a plurality of receiver modules are provided respectively connected to each of the optical selectors. Both the transmitter and receiver modules include byte extraction circuitry that extracts one byte, e.g., the J0 byte, from each of the plurality of frames. Successive bytes are grouped as messages, which are stored in registers so that comparisons can be made between consecutive messages and a predetermined message.

Claims

1. A method for monitoring portions of a data stream, said method comprising the steps of:

extracting each of a first plurality of data segments from a respective one of a first plurality of data frames included in said data stream;

assembling said first plurality of data segments into a first message;

storing said first message in a first memory circuit;

extracting each of a second plurality of data segments from a respective one of a second plurality of frames included in said data stream;

assembling said second plurality of data segments into a second message;

storing said second message in a second memory circuit;

comparing said first message with said second message; and

generating an alarm signal in response to said comparison of said first and second messages.

2. A method in accordance with claim 1, further comprising the step of outputting one of said first and second messages to a user interface device when said first and second messages are different.

3. A method in accordance with claim 1, further comprising the steps of:

storing a predetermined message in a third memory circuit;

comparing one of said first and second messages with said predetermined message; and

outputting said one of said first and second messages to a user interface device when said one of said first and second messages is different than said predetermined message.

4. A method in accordance with claim 1, wherein each of said first plurality of data frames and each of said second plurality of data frames are in a SONET format.

5. A method in accordance with claim 1, wherein each of said first plurality of data frames and each of said second plurality of data frames are in an SDH format.

6. A method in accordance with claim 1, wherein each of said first plurality of data segments and each of said second plurality of data segments include a J0 byte.

7. A method in accordance with claim 6, further comprising the step of generating a B1 byte for each of said first and second pluralities of data franes.

8. A method for monitoring portions of a data stream, comprising the steps of:

extracting each of a plurality of data segments from a respective one of a plurality of data frames included in said data stream;

assembling said plurality of first data segments into a first message;

storing said first message in a first memory circuit;

storing a second predetermined message in a second memory circuit;

comparing said first message with said second predetermined message; and

generating an alarm signal in response to said comparison of said first message and said second predetermined message.

9. A method in accordance with claim 8, further comprising the step of outputting said first message to a user interface device when said first message is different from said second predetermined message.

10. A method in accordance with claim 8, wherein each of said plurality of data frames is in a SONET format.

11. A method in accordance with claim 8, wherein each of said plurality of data frames is in an SDH format.

12. A method in accordance with claim 8, wherein each of said plurality of data segments includes a J0 byte from each of said plurality of data frames.

13. A data communication apparatus, comprising:

a data path carrying a plurality of data frames;

an extraction circuit coupled to said data path, said extraction circuit outputting a plurality of data segments, each of which being selected from a respective one of said plurality of data frames;

a first memory circuit coupled to said extraction circuit, said first memory circuit receiving and storing first ones of said plurality of data segments as a first message;

a second memory circuit coupled to said extraction circuit, said second memory circuit receiving and storing second ones of said plurality of data segments as a second message; and

a comparison circuit coupled to said first and second memory circuits, said comparison circuit comparing said first and second messages and generating an output signal in response to said comparison.

14. A data communication apparatus in accordance with claim 13, further comprising:

a third memory circuit coupled to said comparison circuit, said third memory circuit storing a predetermined message, said comparison circuit further comparing said predetermined message with one of said first and second messages, and generating an additional output signal in response to said comparison of said predetermined message and one of said first and second messages.

15. A data communication apparatus in accordance with claim 13, further comprising:

a control circuit coupled to said extraction circuit and said first and second memory circuits, said control circuit outputting first and second write signals to said first and second memory circuits, said first memory circuit storing said first message in response to said first write signal, and said second memory circuit storing said second message in response to said second write signal.

16. A data communication apparatus in accordance with claim 15, wherein said first and second write signals alternate.

17. A data communication apparatus in accordance with claim 15, wherein said control circuit is further coupled to said third memory circuit, said control circuit further outputting a third write signal to said third memory signal, said third memory circuit storing said predetermined message in response to said third write signal.

18. A data communication apparatus in accordance with claim 13, further comprising:

a user interface device; and

a switch circuit, said switch circuit having first and second inputs coupled to said first and second memory circuits, respectively, and an output coupled to said user interface device, said switch circuit selectively supplying one of said first and second messages to said user interface device.

19. A data communication apparatus in accordance with claim 13, wherein each of said data segments includes a J0 byte.

20. A data communication apparatus in accordance with claim 13, wherein each of said plurality of data frames is in a SONET format.

21. A data communication apparatus in accordance with claim 13, wherein each of said plurality of data frames is in an SDH format.

22. A data communication apparatus, comprising:

an optical-to-electrical conversion element having an input coupled to an optical communication path and an output, said optical-to-electrical conversion element receiving optical signals carried by said optical communication path at said input and generating electrical signals in response thereto at said output;

a data recovery circuit coupled to said optical-to-electrical conversion element, said data recovery circuit generating a stream of data signals in response to said electrical signals, said data signals including a plurality of frames;

an electronic data path coupled to said data recovery circuit and carrying said stream of data signals;

an extraction circuit coupled to said electronic data path, said extraction circuit selecting each of a plurality of data segments from a respective one of said plurality of frames;

a first memory circuit coupled to said extraction circuit, said first memory circuit storing first ones of said plurality of data segments as a first message;

a second memory circuit coupled to said extraction circuit, said second memory circuit storing second ones of said plurality of data segments as a second message; and

a comparison circuit coupled to said first and second memory circuits, said comparison circuit comparing said first and second messages and generating a comparison signal in response thereto.

23. A data communication apparatus in accordance with claim 22, further comprising:

a driving circuit coupled to said electronic data path; and

an optical element coupled to said driving circuit, said driving circuit controlling said optical element in accordance with said stream of data signals.

24. A data communication apparatus in accordance with claim 22, further comprising:

a third memory circuit coupled to said comparison circuit and storing a third predetermined message, said comparison circuit comparing said third predetermined message with one of said first and second messages and generating a further output signal in response thereto.

25. A data communication apparatus in accordance with claim 22, further comprising:

an optical demultiplexer coupled to said optical communication path and being configured to direct said optical signals to said optical-to-electrical conversion element, said optical signals being at a particular wavelength, said optical communication path being configured to carry a plurality of other optical signals, each at a wavelength different than said optical signals directed to said optical-to-electrical conversion element by said optical demultiplexer.