Impairment Aware Path Computation Element Method and System

• US 20130010612A1
• Filed: 07/06/2012
• Published: 01/10/2013
• Est. Priority Date: 07/07/2011
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Lee, Young, Bernstein, Greg
• Granted Patent: US 8,891,382 B2
• Time in Patent Office: Days
• US Class Current: 370/248
• CPC Class Codes: H04B 10/0771 Fault location on the transmission path
• CPC Class Codes: H04B 10/0795 Performance monitoring; Measurement of transmission parameters
• CPC Class Codes: H04B 10/27 Arrangements for networking
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0257 Wavelength assignment algorithms
• CPC Class Codes: H04J 14/0258 Wavelength identification or labelling
• CPC Class Codes: H04J 14/0267 Optical signaling or routing
• CPC Class Codes: H04J 14/0269 using tables for routing
• CPC Class Codes: H04J 14/0271 Impairment aware routing
• CPC Class Codes: H04L 45/123 Evaluation of link metrics techniques for monitoring network metrics H04L43/08
• CPC Class Codes: H04L 45/42 Centralised routing
• CPC Class Codes: H04L 45/62 Wavelength based optical switching H04Q11/0062

Abstract

The disclosure includes an apparatus comprising: a path computation element (PCE) comprising a processor configured to: receive a path computation element protocol (PCEP) path computation request from a path computation client (PCC), wherein the path computation request comprises an impairment validation request that directs the PCE to perform an impairment validation of a network path; after receiving the path computation request, compute a network path; and perform an impairment validation of the network path specified by the impairment validation request. In another embodiment, the disclosure includes a method comprising: sending, by a PCC a PCEP path computation request to a PCE, wherein the request directs the PCE to perform routing and wavelength assignment (RWA) and a first impairment validation of a network path, wherein the request comprises a type of signal quality of the network path which indicates the first type of impairment validation to be performed.

Claims

1. An apparatus comprising:

a path computation element (PCE) comprising a processor configured to;

receive a path computation element protocol (PCEP) path computation request from a path computation client (PCC), wherein the path computation request comprises an impairment validation request that directs the PCE to perform an impairment validation of a network path;

after receiving the path computation request, compute a network path; and

perform an impairment validation of the network path specified by the impairment validation request.

2. The apparatus of claim 1, wherein the PCE is further configured to transmit a PCEP reply to the PCC, and wherein the PCEP reply comprises the computed network path and data indicating whether validation of the network path was successful or unsuccessful.

3. The apparatus of claim 1, wherein the impairment validation request comprises a type of signal quality of the network path which indicates the type of impairment validation to be performed, and wherein, the PCE is configured to perform the impairment validation of the network path based on the type of signal quality.

4. The apparatus of claim 3, wherein the type of signal quality of the network path comprises at least one of Bit Error Limit (BER), Optical Signal to Noise Ratio (OSNR), OSNR margin, Polarization-Mode Dispersion (PMD), and Quality Factor (Q factor).

5. The apparatus of claim 1, wherein the impairment validation request comprises an indicator that indicates whether the impairment validation should be performed at a network path level or at a network path link level, and wherein the PCE performs the impairment validation of the network path based on the indicator.

6. The apparatus of claim 5, wherein the PCE performs the impairment validation of the network path based on the indicator by performing a validation of each link in the network path.

7. The apparatus of claim 5, wherein the PCE performs the impairment validation of the network path based on the indicator by performing a cumulative validation of all links in the network path.

8. The apparatus of claim 4, wherein the impairment validation request comprises a threshold value that indicates the minimum or maximum value of signal quality of a network path or a network path link should satisfy, and wherein the PCE performs the impairment validation of the network path based on the threshold value.

9. The apparatus of claim 8, wherein the PCE performs the impairment validation of the network path based on the threshold value by comparing a signal quality value of the network path, at a path level or at a link level, to the threshold value, wherein if the threshold value comprises a minimum value, the impairment validation is successful if the signal quality value is greater than or equal to the threshold value, and wherein if the threshold value comprises a maximum value, the impairment validation is successful if the signal quality value is less than or equal to the threshold value.

10. The apparatus of claim 9, wherein the PCE further comprises a traffic engineering database (TED), wherein the TED comprises network impairment data, and wherein the PCE uses the network impairment data to determine the signal quality value of the network path.

11. The apparatus of claim 1, wherein the PCE is further configured to transmit an error to the PCC if the path computation request does not comprise a Bit Error Limit (BER).

12. A method comprising:

sending, by a path computation client (PCC), a path computation element protocol (PCEP) path computation request to a path computation element (PCE);

wherein the request directs the PCE to perform routing and wavelength assignment (RWA) and a first impairment validation of a network path; and

wherein the request comprises a type of signal quality of the network path which indicates the first type of impairment validation to be performed.

13. The method of claim 12, wherein the type of signal quality of the network path comprises at least one of Bit Error Limit (BER), Optical Signal to Noise Ratio (OSNR), OSNR margin, Polarization-Mode Dispersion (PMD), and Quality Factor (Q factor).

14. The method of claim 12, wherein the request further comprises an indicator indicating the impairment validation should be performed at a network path level or at a network path link level.

15. The method of claim 14, wherein the request further comprises a threshold value that indicates the minimum or maximum value a network path or a network path link needs to satisfy to be validated.

16. The method of claim 15, wherein a type length value (TLV) is included in the request, and wherein the type length value (TLV) comprises:

a first Signal Quality Type field that comprises the type of signal quality of the network path;

a first Threshold field that comprises the threshold value, and

a first P bit that comprises the indicator.

17. The method of claim 16, wherein the request directs the PCE to perform a second network path impairment validation, and wherein the TLV further comprises:

a second Signal Quality Type field that comprises a second type of signal quality of the network path, a second Threshold field that comprises a second threshold value, and a second P bit that comprises a second indicator.

18. The method of claim 16, wherein the request directs the PCE to perform a second network path impairment validation, and wherein a second TLV is included in the request which comprises a second Signal Quality Type field that comprises a second type of signal quality of the network path, a second Threshold field that comprises a second threshold value, and a second P bit that comprises a second indicator.

19. A method comprising:

performing, by a path computation element (PCE), a first impairment validation of a network path; and

after performing the first network path impairment validation, sending, by the PCE, a path computation element protocol (PCEP) reply to a network node;

wherein the reply comprises a first indicator that indicates whether the first network path impairment validation is successful.

20. The method of claim 19, wherein the reply further comprises a first estimated value of a signal quality of the network path or a link of the network path.

21. The method of claim 20, wherein the reply further comprises a first signal quality type which indicates a type of signal quality used during the first network path impairment validation.

22. The method of claim 20, wherein a type length value (TLV) is included in the reply, and wherein the type length value (TLV) comprises:

a Signal Quality Type field that comprises a type of signal quality used during the first network path impairment validation;

a Signal Quality Value field that comprises the first estimated value of the first signal quality; and

a P bit that comprises the first indicator.

23. The method of claim 21, wherein the PCE performs a second network path impairment validation.

24. The method of claim 23, wherein the reply further comprises:

a second signal quality type which indicates a type of signal quality used during the second network path impairment validation; and

a second estimated value of the second signal quality of the network path or a link of the network path.

25. The method of claim 24, wherein the reply further comprises a second indicator, and wherein the second indicator indicates whether the second network path impairment validation was successful.

26. A method comprising:

receiving, by a path computation element (PCE), a path computation element protocol (PCEP) path computation request (PCReq) message;

wherein the PCReq message includes a measure of signal quality to which computed paths should conform.

27. The method of claim 26, wherein the PCReq comprises at least one of a BER limit, an Optical Signal to Noise Ratio (OSNR), an OSNR margin, a Polarization-Mode Dispersion (PMD), and a Quality Factor (Q factor).

28. The method of claim 26, wherein the PCReq message does not comprise a BER limit, wherein no default BER limit is provisioned at the PCE, and wherein the method further comprises sending, by the PCE, an error message specifying that the BER limit should be provided.

29. The method of claim 26, wherein the PCReq comprises a signal quality measure TLV, and wherein the signal quality measure TLV comprises:

a pass (P) bit that indicates if the signal quality impairment is a path level;

a Signal Quality Type field that indicates a kind of signal quality impairment; and

a Threshold field that indicates a threshold that an signal quality measurement for a path or a link must satisfy.

30. The method of claim 26 further comprising:

sending, by the PCE, a PCEP path computation reply (PCRep) message in response to the PCReq message, wherein the PCRep message comprises a computed path, wavelengths assigned to the path, and an indicator that indicates whether the computed path conforms to the signal quality of the PCReq message.

31. The method of claim 30, wherein if a valid path is not found in response to the PCReq message, the PCRep message comprises a reason why no path was found.

32. The method of claim 30, wherein the PCRep message comprises a signal quality measure TLV, and wherein the signal quality measure TLV comprises:

a P bit that indicates whether an signal quality measurement has passed a threshold;

a Signal Quality Type field that indicates a kind of signal quality impairment; and

a Signal Quality Value field that indicates an estimated value of the signal quality measurement for the computed path.

33. The method of claim 26, wherein the PCReq message is received from a RWA coordinating PCE, and wherein the PCReq message comprises:

an indicator that indicates whether more than one computed path is desired;

a limit to the number of optical impairment qualified computed paths to be returned in the PCRep message; and

a specified path and wavelength to be qualified by the PCE.